Showing posts with label Microsoft. Show all posts
Showing posts with label Microsoft. Show all posts

Microsoft fixes critical Windows kernel, WINS flaws

Microsoft today shipped three security bulletins with fixes for at least 8 documented vulnerabilities affecting millions of Windows OS users.

The most serious of this month’s patch batch is rated “critical” and could allow full remote execution attacks if a Windows user is simply lured into viewing a booby-trapped image file.

The skinny on the March 2009 bulletins:

  • MS09-006: (CRITICAL) Provides cover for three newly discovered and privately reported vulnerabilities in Windows, which could allow remote code execution if a user viewed a specially crafted EMF or WMF image file from an affected system. These vulnerabilities affect all versions of Windows, including Vista and Windows Server 2008. Microsoft expects to see exploit code for these flaws but reckons the reliability will be “inconsistent.”
  • MS09-007: (IMPORTANT): This bulletin includes a patch for a solitary vulnerability in Windows, which could allow spoofing if an attacker gains access to the certificate used by the end user for authentication. Again, Microsoft says “inconsistent exploit code” is likely. The bulletin is available for all versions of Windows — Windows 2000 through Windows Server 2008.
  • MS09-008 (IMPORTANT): This update resolves two privately reported vulnerabilities and two publicly disclosed vulnerabilities in Windows , which could allow a remote attacker to redirect network traffic intended for systems on the Internet to the attacker’s own systems. Microsoft says the patches correct the way that Windows DNS servers cache and validate queries, and by modifying the way that Windows DNS servers and Windows WINS servers handle WPAD and ISATAP registration. For these issues, Microsoft warns that “consistent exploit code” is likely.

Windows users should treat the “critical” bulletin with the highest possible priority.

[Source: zdnet]

Opera plugs security holes; adds ASLR, DEP support

Opera plugs security holes, adds anti-exploit mechanisms Opera Software has shipped a high-priority security patch for its flagship Web browser to plug at least three vulnerabilities that expose Windows users to code execution and cross-domain scripting attacks.

The Opera 9.64 upgrade also adds support for DEP (Data Execution Prevention) and ASLR (Address Space Layout Randomization), two anti-exploitation mechanisms that helps to limit the damage from malware attacks on the Windows platform.

Opera has only released details on one of the three security vulnerabilities, which was discovered and reported by Google’s Tavis Ormandy.

  • Specially crafted JPEG images can cause Opera to corrupt memory and crash. Successful exploitation can lead to execution of arbitrary code.

Opera said the update also fixes an issue where plug-ins could be used to allow cross domain scripting and a third “moderately severe” issue that remains a mystery.

“Details will be disclosed at a later date,” the company said.

* Image source: andyket’s Flickr photostream (Creative Commons 2.0)

[Source: zdnet]

The return of L0phtCrack

More than two years after Symantec pulled the plug on L0phtCrack, the venerable password cracking tool is being prepped for a return to the spotlight.

The original creators of L0phtCrack has reacquired the tool with plans to release a new version at next week’s SOURCE Boston conference.

A teaser post on the l0phtcrack.com Web site mentions “new features and platform support,” which, according to Space Rogue, includes 64-bit Windows support and upgraded rainbow tables.

  • Details on potential additional new features, and pricing have not yet been released but you can bet that it will be better than Symantec’s.

There’s a special session on the return of L0phtCrack scheduled for Thursday March 12 at SOURCE Boston.

Symantec quietly discontinued sales and support for L0phtCrack in 2006 out of concerns that it violated cryptography export controls.

L0phtCrack was a popular tool used to identify and remediate security vulnerabilities that result from the use of weak or easily guessed passwords. It was also used to recover Windows and Unix account passwords to access user and administrator accounts whose passwords are lost or to streamline migration of users to newer authentication systems.

It was originally produced by the L0pht, the Boston-based security research group founded by Peiter “Mudge” Zatko and Chris “Weld Pond” Wysopal.

[Source: zdnet]

URL rewriting can help thwart Web app attacks

A Microsoft Web application security specialist is suggesting an offbeat defense-in-depth strategy to protect Web sites and applications from cross-site scripting (XSS) and cross-site request forgery (XSRF) attacks.

According to Bryan Sullivan, security program manager for Redmond’s Security Development Lifecycle team, Web developers should consider URL Rewriting as a technique to ward off hackers looking to exploit Web app vulnerabilities.

Here’s the gist of Sullivan’s recommendation:

  • Attacks like cross-site scripting (XSS), cross-site request forgery (XSRF), and open-redirect phishing are routinely propagated through malicious hyperlinks sent in e-mail messages. (If you’re unfamiliar with these attacks, I recommend reading about them at the Open Web Application Security Project (OWASP) Web.) We could mitigate much of the risk of these vulnerabilities by frequently changing our URLs — not once every 200 years but once every 10 minutes. Attackers would no longer be able to exploit application vulnerabilities by mass e-mailing poisoned hyperlinks because the links would be broken and invalid by the time the messages reached their intended victims.

Of course, there are some caveats, especially in cases where bookmarking and e-mailing static links are necessary:

  • URL rewriting may not be appropriate for all applications. One negative side effect of this approach is that although attackers are no longer able to e-mail malicious hyperlinks, legitimate users are similarly prevented from sending valid links or even from bookmarking pages in the application. Any page marked as a landing page could be bookmarked, but as I mentioned before, you need to be very cautious when using landing pages. Therefore, if you expect users of your application to bookmark pages other than the home page, URL rewriting is probably not a good solution for you.
  • Additionally, while URL rewriting is a fast and easy defense-in-depth mechanism, it is just that: defense-in-depth. It is by no means a silver bullet against XSS or any other attacks. An automatically expiring URL can still be exploited by an attacker with access to a Web server of his own. Instead of sending out malicious hyperlinks that point directly to the vulnerable page, he can send out hyperlinks that point to his own site. When his site gets a hit from one of the phished e-mails, it can contact a landing page on the vulnerable site to obtain a valid time stamp and then redirect the user accordingly.

Sullivan argues that URL rewriting does make the attacker’s work more difficult: he now has to convince a user to follow a hyperlink to his Web site (evil.contoso.com) rather than a trusted one (www.msn.com), and he is also leaving a very clear trail back to himself for law enforcement agencies to follow. However, this will probably be of little comfort to any victims who fall for the phished e-mail and have their identities stolen as a result.

  • Do use URL rewriting as an extra defensive measure, but always be sure to address vulnerabilities at the root of the problem.

Read the entire article here.

[Source: zdnet]

Microsoft takes aim at Vista 'SoftMod' hack

Starting this week, Microsoft will ship an update to Windows Vista Ultimate users to ferret out cracked copies of its most expensive and feature-packed operating system.

The renewed anti-piracy campaign is aimed directly at the activation exploit known as the “SoftMod hack,” according to a post on Microsoft’s WGA blog.

This Knowledge Base article explains:

  • This update enables Windows Vista to detect activation exploits that bypass product activation and that interfere with usual Windows operation. An activation exploit is a form of software that replaces or modifies authentic Windows components. When activation exploits are present on a system, it indicates that a software or hardware vendor may have tampered with genuine Windows to enable the sale of counterfeit software. Therefore, the security and the privacy of the computer are put at risk. After this update is installed, you will know if activation exploits are present on the system.

According to Alex Kochis, director of Microsoft’s Windows Genuine group, this is what a user would see on a system that has detected the SoftMod activation exploit:

* Hat tip: Gregg Keizer.

[Source: zdnet]

Microsoft: ‘Consistent exploit code likely’ for IE vulnerabilities

Microsoft today shipped four bulletins with patches for at least 8 documented security vulnerabilities affecting Windows users and warned that “consistent exploit code could be easily crafted” to launch attacks via the Internet Explorer browser.

The Patch Tuesday batch includes fixes for a pair of code execution holes in IE, two bugs in the Microsoft Exchange Server, a remote code execution issue in the Microsoft SQL Server, and three separate flaws haunting users of Microsoft Office Visio.

The Internet Explorer bulletin (MS09-002) should be treated with urgency because the flaws can be exploited to launch drive-by download attacks.

  • This security update is rated Critical for Internet Explorer 7 running on supported editions of Windows XP and Windows Vista. For Internet Explorer 7 running on supported editions of Windows Server 2003 and Windows Server 2008, this security update is rated Moderate.

The Microsoft warning that consistent exploit code was likely suggests that it’s very easy for an attacker to host a specially crafted Web site and attack unpatched users who surfed to the rigged Web site.

  • The attacker could also take advantage of compromised Web sites and Web sites that accept or host user-provided content or advertisements. These Web sites could contain specially crafted content that could exploit this vulnerability.

Enterprise administrators will also want to pay special attention to the Microsoft Exchange update (MS09-003) which covers two different vulnerabilities that expose users to code execution or denial-of-service attacks.

Microsoft explains:

  • The first vulnerability could allow remote code execution if a specially crafted TNEF message is sent to a Microsoft Exchange Server. An attacker who successfully exploited this vulnerability could take complete control of the affected system with Exchange Server service account privileges. The second vulnerability could allow denial of service if a specially crafted MAPI command is sent to a Microsoft Exchange Server. An attacker who successfully exploited this vulnerability could cause the Microsoft Exchange System Attendant service and other services that use the EMSMDB32 provider to stop responding.

The company says it expects to see “inconsistent exploit code” published for this bulletin. However, nCircle director of security operations Andrew Storms says this is a very serious problem.

“This vulnerability means that any cybercriminal sending a well crafted email attachment to an enterprise could gain complete control over the server and gaining one of the keys to the kingdom,” Storms said.

“All kinds of highly confidential and proprietary information pass through an Exchange server every day. Gaining control over it and its content would be a gold mine to any cyber criminal,” he added.

[Source: zdnet]

Targeted malware attacks exploiting IE7 flaw detected

Researchers at TrendMicro have detected a targeted malware attack exploiting last week’s patched critical MS09-002 vulnerability affecting Internet Explorer 7. Upon opening the spammed Microsoft office document, vulnerable users are automatically forwarded to a Chinese live exploit site which still remains active.

The attack has also been confirmed by McAfee and by the ISC, who point out that the cybercriminals appear to have reverse engineered Microsoft’s patch in order to come up with the exploit.

From TrendMicro’s post:

The threat starts with a spammed malicious .DOC file detected as XML_DLOADR.A. This file has a very limited distribution script, suggesting it may be a targeted attack. It contains an ActiveX object that automatically accesses a site rigged with a malicious HTML detected by the Trend Micro Smart Protection Network as HTML_DLOADER.AS.

HTML_DLOADER.AS exploits the CVE-2009-0075 vulnerability, which is already addressed by the MS09-002 security patch released last week. On an unpatched system though, successful exploitation by HTML_DLOADER.AS downloads a backdoor detected as BKDR_AGENT.XZMS.

This backdoor further installs a .DLL file that has information stealing capabilities. It sends its stolen information to another URL via port 443.

The attackers trade-off in this case is to either launch a less noisy targeted attack, or attempt to target as many users as possible by using legitimate web sites as infection vectors, a choice that depends on what they’re trying to achieve, and who are they targeting in particular.

Who’s behind the attack anyway? The web service (9966.org) used as a “phone back” location with the stolen data, is a well known one used primarily by Chinese hackers in previous massive SQL injections attacks, which doesn’t necessarily mean the campaign is launched by Chinese hackers, since it could be international hackers from anywhere using a well known malicious infrastructure in order to forward the responsibility to local hackers.

Moreover, in this particular campaign I can easily argue that the window of opportunity for abusing this vulnerability in a targeted fashion, is just as wide open as attempting to exploit the same hosts by diversifying the use of different exploits. For instance, despite the timely exploitation of MS09-002, based on the number of Conficker affected hosts globally, a situation where once again a patch is present, there’s a great chance that some of the hosts they’re attempting to exploit through the use of MS09-002 are already part of Conficker’s botnet, or remain susceptible to outdated vulnerabilities.

So far, no massive malware campaigns are taking advantage of the exploit, but users are advised to self-audit themselves against known client-side vulnerabilities and MS09-002 in particular.

[Source: zdnet]

Apple Patch Day: Gaping Mac OS X, Safari holes

It’s Apple’s turn on the Patch Day treadmill and, for Mac OS X users, it’s quite ugly.

As I write, Apple has released four different bulletins to cover 48 documented vulnerabilities in the Mac OS X ecosystem, a solitary code execution flaw affecting Safari for Windows and four different security problems in Java for Mac OS X.

Security Update 2009-001 is quite a whopper, providing patches for holes in a wide range of components, including several open-source implementations like ClamAV and fetchmail.

[ How does Apple get away with this badware behavior? ]

This is a high-priority update for all Mac OS X users so don’t fool around when you see that Software Update alert. All the raw details can be found in this advisory.

If you’re a Windows user and Safari is installed on your machine, pay special attention to this alert, which warns of code execution exposure on Windows XP and Windows Vista.

  • Multiple input validation issues exist in Safari’s handling of feed: URLs. The issues allow execution of arbitrary JavaScript in the local security zone. This update addresses the issues through improved handling of embedded JavaScript within feed: URLs.

[ Pwn2Own hacker contest targets browsers, smart phones ]

Apple also shipped a Java for Mac update with fixes for 4 more security problems:

  • Multiple vulnerabilities exist in Java Web Start and the Java Plug-in, the most serious of which may allow untrusted Java Web Start applications and untrusted Java applets to obtain elevated privileges. Visiting a web page containing a maliciously crafted Java applet may lead to arbitrary code execution with the privileges of the current user.
[Source: zdnet]

Inside Microsoft’s February patch batch

Apply IE emergency update now, don’t ask questions — Eric Schultze

It’s a seemingly light batch of patches this month, trailing an even lighter, single patch release in January. Two critical items were released — including patches for Internet Explorer 7 and Microsoft Exchange Server. Additionally, two “important” items were released — for Microsoft SQL Server and Visio.

MS09-002 is a typical IE patch, providing protection if a user is surfing to an evil website. What’s unusual this month is that the vulnerability is only present in Internet Explorer 7. This leads to the question “what did Microsoft put in IE7 that they didn’t put in earlier versions that leads to this exploit, and why didn’t their new security testing program catch this vulnerability?”


[ SEE: Microsoft: ‘Consistent exploit code likely’ for IE vulnerabilities ]

Microsoft says that it’s easy for hackers to create an evil webpage to exploit this issue.

MS09-003 is a Critical patch for Exchange Server (versions 2000, 2003, 2007) that could lead to code execution and/or Denial of Service. The attacker can send a malformed winmail.dat file to an Exchange Server in hopes of having that server execute code of their choosing. (winmail.dat files are configuration files that instruct the email client how to render and display Rich Text Formatted documents.) Alternatively, the attacker can send a series of packets to the Exchange Server in an attempt to take down the mail services - creating a denial of service attack. Microsoft says that inconsistent exploit code is likely to be released.

MS09-004 is probably the most interesting patch this month. This patch addresses the zero-day SQL Server flaw reported by Sec-Consult on December 9th, 2008. This flaw enables attackers to execute code of their choice on the affected SQL Server. The bar for exploitation is raised slightly in that the attacker must already have authenticated access to the SQL Server in order to pull of this exploit.

[ SEE: Microsoft confirms critical SQL Server vulnerability ]

However, unauthenticated attackers (since when you do authenticate your attacker anyway?) can still leverage this flaw if they can plant their code using SQL Server injection techniques via poorly coded websites. Proof of concept code has been published on the Internet but Microsoft says they have not seen proof of exploitation (maybe they aren’t looking hard enough?). I’d probably rate this patch as Critical - given the end result capable. I’m guessing Microsoft has downgraded this severity because of the “authentication” requirement. (although they give this a ‘1′ in the exploitability index - saying that consistent exploit code is likely).

MS09-005 is an Important patch for Visio. Open a malformed Visio document and the evil-doer can run code on your system in the context of your currently logged on account. Microsoft says this was privately reported and they’ve seen no reports of exploitation. They recommend not opening Visio documents from untrusted sources.

[ SEE: BlackBerry bitten by ActiveX control flaw ]

I recommend a two pronged approach to patching this month. Two patches are for Server issues (09-003 and 4 - Exchange and SQL) and two are for client side applications (09-002 and 5 - IE7 and Visio). Give the two server patches to the Server maintenance team and ask that they install these two as soon as possible - given what I believe is the severity of these issues. Give the two client side patches to the desktop team and have them install these patches in the next update cycle or as they see fit - but no need to burn the weekend candle for these.

* Eric Schultze is chief technology officer at Shavlik Technologies, a vulnerability management company.

[Source: zdnet]

Microsoft: ‘Consistent exploit code likely’ for IE vulnerabilities

Microsoft today shipped four bulletins with patches for at least 8 documented security vulnerabilities affecting Windows users and warned that “consistent exploit code could be easily crafted” to launch attacks via the Internet Explorer browser.

The Patch Tuesday batch includes fixes for a pair of code execution holes in IE, two bugs in the Microsoft Exchange Server, a remote code execution issue in the Microsoft SQL Server, and three separate flaws haunting users of Microsoft Office Visio.

The Internet Explorer bulletin (MS09-002) should be treated with urgency because the flaws can be exploited to launch drive-by download attacks.

  • This security update is rated Critical for Internet Explorer 7 running on supported editions of Windows XP and Windows Vista. For Internet Explorer 7 running on supported editions of Windows Server 2003 and Windows Server 2008, this security update is rated Moderate.

The Microsoft warning that consistent exploit code was likely suggests that it’s very easy for an attacker to host a specially crafted Web site and attack unpatched users who surfed to the rigged Web site.

  • The attacker could also take advantage of compromised Web sites and Web sites that accept or host user-provided content or advertisements. These Web sites could contain specially crafted content that could exploit this vulnerability.

Enterprise administrators will also want to pay special attention to the Microsoft Exchange update (MS09-003) which covers two different vulnerabilities that expose users to code execution or denial-of-service attacks.

Microsoft explains:

  • The first vulnerability could allow remote code execution if a specially crafted TNEF message is sent to a Microsoft Exchange Server. An attacker who successfully exploited this vulnerability could take complete control of the affected system with Exchange Server service account privileges. The second vulnerability could allow denial of service if a specially crafted MAPI command is sent to a Microsoft Exchange Server. An attacker who successfully exploited this vulnerability could cause the Microsoft Exchange System Attendant service and other services that use the EMSMDB32 provider to stop responding.

The company says it expects to see “inconsistent exploit code” published for this bulletin. However, nCircle director of security operations Andrew Storms says this is a very serious problem.

“This vulnerability means that any cybercriminal sending a well crafted email attachment to an enterprise could gain complete control over the server and gaining one of the keys to the kingdom,” Storms said.

“All kinds of highly confidential and proprietary information pass through an Exchange server every day. Gaining control over it and its content would be a gold mine to any cyber criminal,” he added.

[Source: zdnet]

MS Tuesday heads-up: Critical IE, Exchange flaws

Microsoft plans to ship four security bulletins next Tuesday with patches for a range of serious security vulnerabilities affecting millions of Windows users.

Two of the four bulletins will be rated “critical,” Microsoft’s highest severity rating. Those will cover remotely exploitable flaws in the Internet Explorer browser and the Microsoft Exchange Server.

[ GALLERY: How to configure Internet Explorer to run securely ]

The other two bulletins will carry an “important” severity rating and will provide fixes for code execution holes in Microsoft SQL Server and Microsoft Office (Visio).

The Internet Explorer update will apply to all supported versions of the Windows operating system, including Windows Vista and Windows Server 2008.

[Source: zdnet]

US-CERT warning: Windows does not disable AutoRun properly

US-CERT: Windows does not disable AutoRun properly

The U.S. Computer Emergency Readiness Team (US-CERT) has issued a technical cyber-security alert to warn that Microsoft’s guidelines for disabling AutoRun in the Windows operating system “are not fully effective” and argues that this “could be considered a vulnerability.”

The U.S. CERT warning comes on the heels of live malware/worm attacks that take advantage of the Windows AutoRun and AutoPlay features to improve propagation.

[ SEE: Is there no end to the AutoRun madness? ]

Here’s the skinny on Microsoft’s hiccup:

  • The Autorun and NoDriveTypeAutorun registry values are both ineffective for fully disabling AutoRun capabilities on Microsoft Windows systems. Setting the Autorun registry value to 0 will not prevent newly connected devices from automatically running code specified in the Autorun.inf file. It will, however, disable Media Change Notification (MCN) messages, which may prevent Windows from detecting when a CD or DVD is changed. According to Microsoft, setting the NoDriveTypeAutorun registry value to 0xFF “disables Autoplay on all types of drives.” Even with this value set, Windows may execute arbitrary code when the user clicks the icon for the device in Windows Explorer.

This means that malware authors can place an Autorun.inf file on a device to automatically execute arbitrary code when the device is connected to a Windows system. Code execution may also take place when the user attempts to browse to the software location with Windows Explorer, US-CERT warned.

The alert includes instructions for editing the registry to properly disable AutoRun in Microsoft Windows.

UPDATE: Microsoft sent me an e-mail to point out that its KB953252 document, published in May 2008, describes how to correct the problem of NoDriveTypeAutoRun registry value enforcement. This prompted an update on the US-CERT notice:

After the update is installed, Windows will obey the NoDriveTypeAutorun registry value. Note that this fix has been released via Microsoft Update to Windows Vista and Server 2008 systems as part of the MS08-038 Security Bulletin. Windows 2000, XP, and Server 2003 users must install the update manually. Our testing has shown that installing this update and setting the NoDriveTypeAutoRun registry value to 0xFF will disable AutoRun.

[Source: zdnet]

Phishing without bait: The in-session password theft attack

In-session password theft attacksSkilled identity thieves can pilfer user names, passwords and other sensitive data for banking sites without using e-mail lures and other other social engineering tactics.

According to a security advisory from Trusteer, hackers can launch what is described as “in-session phishing attacks” using pop-up messages during an active browser session. The attack technique is somewhat sophisticated — it requires that a base Web site is compromised and the attacker must know which Web site the victim user is currently logged into — in-session phishing can be highly effective because the average end user is likely to enter credentials without a second thought.

Here’s how it works:

  1. A user logs onto their online banking application. Leaving this browser window open, the user then navigates to other Web sites.
  2. A short time later a pop-up box appears, allegedly from the banking website, requesting the user re-type their username and password because the session has expired, or complete a customer satisfaction survey, or participate in a promotion, etc.
  3. Since the user had recently logged onto the banking website, he/she will likely not suspect this pop-up is fraudulent and thus provide the requested details.

To mount a successful in-session phishing attack, a base Web site must be compromised (check!), the malware injected onto the hijacked Web site must be able to identify the site the user is logged into (not trivial but very possible).

Trusteer has issued a research paper (.pdf) that calls attention to a vulnerability in the JavaScript engine of all leading browsers — Internet Explorer, Firefox, Safari, and Chrome — which allows a Web site to check whether a user is currently logged onto another website.

The source of the vulnerability is a specific JavaScript function. When this function is called it leaves a temporary footprint on the computer and any other website can identify this footprint. Websites that use this function in a certain way are traceable. Many websites, including financial institutions, online retailers, social networking websites, gaming, and gambling websites use this function and can be traced.

It explains how a skilled attacker can program a compromised website needs to maintain a list of sites it wants to check.

There is no limit to the number of URLs that a compromised website can check for logged on users. It simply asks the browser a simple question: “is the user currently logged onto this specific website?” and the browser will answer “yes” or “no”. Once the compromised website identifies a website to which the user is logged on, it can inject a pop up message in the browser pretending to be from the legitimate website and asking for credentials and private information.

To protect themselves from in-session phishing attacks, Trusteer recommends that users:

  1. Deploy Web browser security tools.
  2. Always log out of banking and other sensitive online applications and accounts before navigating to other websites.
  3. Be extremely suspicious of pop ups that appear in a web session if you have not clicked a hyperlink.

* Image source: ToastyKen’s Flickr photostream (Creative Commons 2.0)

[Source: zdnet]

Malware author greets Microsoft’s Windows Defender team

Zlob malware familyA Russian malware author with involvement in the Zlob malware family, one of the most prolific malware families in 2008 thanks to its successful mimicking of video codecs, has left a message for the Windows Defender team inside a sample analyzed by French researchers. The message is a follow-up to a previous note left in October, and is basically greeting Microsoft in respect to their improving detection rates for this malware family.

For Windows Defender’s Team:
I saw your post in the blog (10-Oct-2008) about my previous message. Just want to say ‘Hello’ from Russia. You are really good guys. It was a surprise for me that Microsoft can respond on threats so fast. I can’t sign here now (he-he, sorry), how it was some years ago for more seriously vulnerability for all Windows ;) Happy New Year, guys, and good luck! P.S. BTW, we are closing soon. Not because of your work. :-)) So, you will not see some of my great ;) ideas in that family of software. Try to search in exploits/shellcodes and rootkits. Also, it is funny (probably for you), but Microsoft offered me a job to help improve some of Vista’s protection. It’s not interesting for me, just a life’s irony.

Who’s this guy? The malware author claims that has coded a critical vulnerability affecting Windows a couple of years ago, and that Microsoft has once offered him a job presumably as a researcher. This message clearly indicates the ongoing multitasking mode of cybercriminals. Moreover, even though the author is trying to distance himself from future Zlob releases, the malware family is not going away anytime soon despite that his campaigns have been somehow affected by Microsoft and, of course, the community as a whole.

The reason for that is the affiliation-based model (Inside an affiliate spam program for pharmaceuticals; Botnets committing click fraud observed) cybercriminals have been developing throughout the entire 2008, forwarding the process of dissemination and coming up with lower detection rates to the binaries to third-parties who earn money in the process as long as the infected hosts phone back to desired location. This affiliation-based model is the main factor for the growth of the Zlob malware, now an inseparable part of the underground ecosystem as one of the key promotional tools for fake security software.

[Source: zdnet]

MS Patch Tuesday: 3 critical SMB vulnerabilities

3 critical SMB vulnerabilitiesMicrosoft today shipped a solitary bulletin with patches for at least three documented security flaws in the Microsoft Server Message Block (SMB) Protocol.

The three vulnerabilities, rated “critical” on Windows 2000, Windows XP and Windows Server 2003, exposes Windows users to remote code execution attacks, Microsoft said in its MS09-001 bulletin. The company warns:

“An attacker who successfully exploited these vulnerabilities could install programs; view, change, or delete data; or create new accounts with full user rights.”

Only two of the three vulnerabilities affect Windows Vista and Windows Server 2008.

Although the exposure to risk seems severe (remote code execution), Microsoft believes it’s unlikely that functioning exploit code will be created and released. Microsoft’s Mark Wodrich explains why:

  • The vulnerabilities cause a fixed value (zero) to be written to kernel memory – not data that the attacker controls.
  • Controlling what data is overwritten is difficult. To exploit this type of kernel buffer overrun, an attacker typically needs to be able to predict the layout and contents of memory. The memory layout of the targeted machine will depend on various factors such as the physical characteristics (RAM, CPUs) of the system, system load, other SMB requests it is processing, etc.

Eric Schultze, CTO at patch management specialists Shavlik, still recommends that Windows users view at MS09-001 as “super critical to install right away.”

This flaw enables an attacker to send evil packets to a Microsoft computer and take any action they desire on that computer - no credentials required. The only pre-requisite for this attack to be successful is a connection from the attacker to the victim over the NetBIOS (File and Printer Sharing) ports (tcp 139 or 445). By default, most computers have these ports turned on.

While these ports are usually blocked on Internet firewalls and personal firewalls, these ports are typically left open in a corporate network. If a worm is released, and that worm makes it into a corporate network, it will make swiss cheese of that network relatively quickly.

According to Roel Schouwenberg, a senior anti-virus researcher at Kaspersky Lab (my employer) the risk of a network worm attack is minimal. “It’s unlikely we’ll see a worm,” he said.

[Source: zdnet]

Microsoft planning quiet Patch Tuesday (1 critical)

Microsoft to patch Windows worm holeMicrosoft plans to ship a solitary security bulletin next Tuesday with fixes for a serious security problem in its flagship Windows operating system.

The bulletin will carry a “critical” rating, which means that exploitation of the vulnerability could allow the propagation of an Internet worm without user action.

According to an advance notice issued by Redmond, the flaw is rated critical on Windows 2000, Windows XP and Windows Server 2003.

On Windows Vista and Windows Server 2008, the severity is downgraded to “moderate.”

Technical details on this issue will not be publicly available until Microsoft ships the patch on January 13, 2009.

[Source: zdnet]

Microsoft study debunks phishing profitability

Phishing PagesDo phishers actually make money, or is phishing an unprofitable business, scammers lose time and resources into? Taking the economic approach of generalizing how much money phishers make, a recently released study by Microsoft researchers Cormac Herley and Dinei Florencio (A Profitless Endeavor: Phishing as Tragedy of the Commons), states that phishing isn’t as profitable as originally thought.

Citing a 1968 published article “Tragedy of the Commons” the researchers argue that due to the fact that so many phishers operate on the same scam-scene, they earn less than the could possibly do. Moreover, according to the research the enormous volume of phishing emails is in fact an indication of the failure of phishing. Naturally, they are many more factors to consider, in particular, are phishers in fact profit-maximization machines or are they willing to sacrifice potential profit for the sake of their own security? Is it all about making big money, or about breaking-even in general?

“However, as we will show, the economics of phishing are far far worse than this. Rather than sharing a fixed pool of dollars phishing is subject to the tragedy of the commons ; i.e. the pool of dollars shrinks as a result of the efforts of the phishers. A community (all phishers) share a finite resource (the pool of phishable dollars) that has limited ability to regenerate (dollars once phished are not available to other phishers). The tragedy of the commons is that the rational course of action for each individual (phisher) leads to over-exploitation and degradation of the resource (the phishable dollars).”

Using the Tragedy of the Commons analogy in this case makes it sound as every phished person’s disposable income to which phishers would eventually have access to is universally the same. Logically, that’s not the case, since a single phished person could prove to be a more profitable catch for a phisher than a hundred phished people, and the number of potentially phishable people is always increasing with more people going online.

Moreover, perhaps not so economic models minded phishers are constantly looking for ways to achieve better efficiency, lower costs, and ways to eat other phishers lunch - by scamming their fellow colleagues. For instance, a related research published in August, 2008, found evidence that phishers are in fact backdooring phishing pages and then distributing them for free so that they can have other phishers do the scam for them. The same backdooring process, even though no properly analyzed in a study, continues to take place at a more advanced and far more profitable level - backdooring web malware exploitation kits and botnet command and control interfaces. Therefore, of the hundred actively participating phishers, eighty could be easily phishing for the other twenty.

There are even more variables to consider. Take internal competition among different phishers. Just because a phisher has just sent a million phishing emails pretending to be from a leading German bank to a million Chinese users, perhaps not knowing that the spamming database he’s using belongs to Chinese citizens, doesn’t mean that the outcome of his campaign would be similar to a fellow phisher that’s taken basic localization and targeting steps into account. With localization of cybecrime taking place as of early 2008, outsourcing the translation process of a particular phishing campaign/email is opening up an entire new space for phishers to more effectively target potential victims. The bottom line here is that the second phisher has a higher chance for success even though they’re attempting to phish the same Chinese users, since he’d be impersonating a local bank and his phishing creatives would be speaking native language.

This is where efficiency and scalability comes into play, a situation pretty similar to that of spam. As long as even a small number of people out of a million phishing emails sent become victims, the phishers would break-even and thus, continue expanding the number of emails sent. This shouldn’t be taken as a failure of phishing in general, instead, it should be considered as a campaign optimization practice attempting to achieve better results by targeting a larger population.

DIY Phishing KitQuality assurance is yet another differentiation factor distinguishing the sophisticated phisher from the novice one, who will never get close to the potential market share the sophisticated one is aiming at. Just because all phishers have access to the same quality fakes of legitimate banks, and DIY phishing tools assisting them in redirecting accounting data to a single domain, doesn’t mean that all of them will make the same impact. The experienced ones would achieve a higher average online time for their phishing domains, and would apply better targeting and localization tactics due to the fact that spammers, phishers and malware authors are consolidating and vertically integrating to cut costs and achieve scalability. Phishing may be described as a low-skill, low-reward job in the study, but just like every cybercrime practice the “knowledge workers” in the phishing ecosystem are those getting most of financial rewards, with the rest basically generating noise and in fact often getting busted due to their inexperience, acting as a human shield for the sophisticated phishers.

There’s another issue to consider and that is how much money is a phisher actually looking to make out of his phishing campaigns, and is there in fact a maximum or a minimum to his ambitions? Even though access to someone’s account is obtained, is the phisher actually able to withdraw the money from the account, or is he in fact going to be making money from selling access to the phished account to someone who can do it, thus, monetizing the accounting data instead of using it? Evidence gathered on this practice clearly indicates that novice phishers may in fact never obtain any of the money that they have access it, but again make money out of selling the access to a particular account to those who can.

Phishers may not be making the money that they used to a couple of years ago, but then again phishing has long stopped being an exclusive cybercrime practice - it’s turned into a cybercrime practice “in between” with the phishers breaking-even given the lowering costs and entry barriers into the phishing space in general. And as long as they break-even, millions of phishing emails would continue circulating, again “in between” the rest of their malicious activities.

[Source: zdnet]

Adobe Flash, Apple Safari fail privacy test

Adobe Flash, Apple Safari fail privacy testsThird party plug-ins like Adobe Flash do a poor job of cleaning traces of your browser sessions, rendering private-browsing features somewhat useless, according to a new study by researcher Katherine McKinley.

McKinley, a researcher at iSec Partners, created a tool for testing the functionality of clearing private data after a browser session and browsing in private mode and found that some browsers — most notably Apple’s Safari for Windows — do a poor job of wiping traces of a browser session.

[ SEE: Microsoft confirms ‘InPrivate’ IE 8 ]

McKinley warns (.pdf):

Third party plug-ins like Adobe Flash, which is far more popular than any individual browser or platform, seem to undermine the data protection schemes offered by all common browsers, however. While browsers are introducing more features with privacy implications, such as persistent local storage, they have mostly integrated the management of this type of information into a single location. When users want to ensure their privacy with respect to information stored via the browser standard methods, they can go to a single location to clear the data, use a separate browser, or use a working private browsing mode, if available.

Plug-ins need to take extra steps to ensure the privacy of their users. The clear best practices in this area, as exemplified by Google’s Gears, prompts users before allowing a site to store data on their system, holds a per-browser data store, and integrates their management UI into the browser UI. Adobe Flash does none of these things, instead silently allowing web sites to store data, uses one global data store for all browsers, and uses a settings UI accessible only when the user is connected to the Internet.

[ SEE: Major Web browsers fail password protection tests ]

She called on browser vendors and plug-in vendors to cooperate to make their platforms more trustworthy:

A set of standard APIs to communicate the need for plug-ins to clear data for a particular origin, all sites, or even a date range needs to be developed, and its use required of all plugins. In the absence of these APIs, plugins which require use of any local system resources should prompt before allowing web sites to store data locally, and integrate the management of interface into the standard browser API.

In the study, McKinley tested the data storage on modern browsers, including HTTP cookies, HTML 5 session storage, Mozilla Firefox perisistent storage, HTML 5 database storage, IE userData, Adobe Flash and Google Gears.

[ SEE: Firefox scrambles to add ‘private mode’ browsing ]

Apple’s Safari on Windows, which offers a “Private Browsing” option, did not fare well:

The HTML 5 Database store on Safari is not cleared when resetting the private data, the user must go to their preferences and select Security, then click the “Show Databases” button on that tab to review or delete databases. For IE 8 Beta 2, the browser must be closed to actually clear the data for the running instance. In each of these cases, it is necessary to perform additional actions to effectively clear this data.

And more:

Safari on Windows fared the worst of all in [tests] with respect to private browsing, and did not clear any data at all, either before entering or after exiting the private mode. On OS X, Safari’s behavior was quirky; in no case was the HTML 5 database storage cleared before or after private browsing. Previously set cookies seem to continue to be available if the user entered a private browsing session, but if the user started the browser and went directly into private browsing, it seemed to behave as expected.

* Image source: 253C. Hat tip to NYT’s Brad Stone.

[Source: zdnet]

An easy fix ignored

An easy fix ignoredIn the wake of this morning’s 25C3 presentation by Alex Sotirov and Jacob Appelbaum, most of the coverage I’ve read so far has focused on the technical details and real-world impact of their findings. Rightly so — their paper describing the attack is a fascinating read filled with enough gory details to make any security practitioner salivate.

To summarize, the crux of the attack was the fact that certain certificate authorities (CAs) still use the MD5 algorithm to sign SSL certificates. The researchers exploited this implementation by harnessing some existing academic research on MD5 chosen-prefix collisions and sprinkling in a few additional tricks.

The most frustrating part of this whole debacle is that it should have never happened.

Like any widely-used cipher, MD5 has been scoured for weaknesses by crypt-analysts since its introduction in 1991. The first significant cracks in the surface appeared at the CRYPTO 2004 conference in August 2004, when Xiaoyun Wang presented a paper entitled Collisions for Hash Functions that described a method for producing MD5 collisions.

[ SEE: SSL broken! Hackers create rogue CA certificate using MD5 collisions ]

History has shown repeatedly that cryptanalysis is an evolutionary process. Each subsequent compromise builds on top of prior work, and each new attack is more practical than the last. The Wang presentation should have been a wake-up call that the clock was ticking on MD5. But, aside from the security community, nobody paid much attention.

At the time, I was employed as a security consultant for @stake, and I can remember revising all of our deliverable templates to remove any mention of MD5 from our best practices or boilerplate text. Even some of my own colleagues were split on whether that was necessary, since the attack didn’t have any practical implications yet. I agreed that we had no reason to act like the sky was falling, but it would only be a matter of time until a practical attack would be discovered. As such, our customers should be advised, at the very least, to eradicate MD5 from their code going forward.

But people tend to be lazy. The typical enterprise mindset can best be summarized as “if it can’t hurt me today, stop bothering me,” and that probably won’t change anytime soon. For an enterprise application, the risk is bounded. If you choose to use a weak hash algorithm in your custom web application, you only hurt yourself and your customers. Apparently, that is a risk people are willing to take, even though switching hash algorithms is a fairly trivial code modification.

A few years later, right on cue, Marc Stevens released a master’s thesis entitled On Collisions in MD5 (.pdf), detailing a chosen-prefix attack against MD5. This was a significant breakthrough and one crucial step closer to the practical, real-world attack revealed today in Berlin.

It’s an absolute travesty that the CAs failed to act not only on the Wang research, but on every other MD5 attack that has materialized since. Any organization who is in the business of selling trust should take all possible measures to be trustworthy, and the CAs failed miserably in that regard.

* Chris Eng is senior director of security research at Veracode. He is currently removing root CAs from his web browser.

[Source: zdnet]

MD5/rogue CA attack: The sky is not falling

Guest post by John Viega

John Viega Today there’s been a lot of buzz about the clever new attack on public key infrastructure from Alex Sotirov and a team of researchers. In the attack, the bad guy ends up with his own Certification Authority (CA) that is fully trusted according to every major browser. People are declaring the entire Internet is broken, and that it will be hard to fix. This is simply not true.

The major misconception I’m seeing over and over is that the problem allows the bad guy to steal the signature off any valid MD5 signature from any certificate on the Internet.


[ SEE: SSL broken! Hackers create rogue CA certificate ]

Actually, the attack works by a bad guy generating two certificates, one that is just a regular web site certificate, and the other that is a CA certificate. Then, to get the CA certificate trusted, the bad guy submits the web site cert. If he can predict the internal values the CA will use when he starts generating the certificate (a process that takes a few days right now), then he will get back a signature that can be pasted onto the CA cert. That allows the CA to generate new certs to impersonate anybody on the Internet (e.g., Citibank.com).

This means that existing certificates aren’t currently an attack vector, unless they were actually used in an attack.

As a result, this hole is easier to close than people think. The few CAs signing certs with MD5 need to switch to SHA1 (or something stronger). That immediately gets rid of the problem for new certs.

[ Chris Eng: An easy fix ignored ]

For old certs, the risks are also pretty low. Just because of the up-front costs of research and development that would have been necessary, there’s a very good chance that bad guys have focused on low-hanging fruit like social engineering, instead of investing the research dollars.

Once the researchers publish technical details on the tricks they used to make the attack cost effective, then probably some bad guys will try, as long as there are still vulnerable CAs. My guess is that there won’t be.

Even if some bad guys have done all the work, it’s unlikely to have been used more than a handful of times. Either the bad guys will use their fake CA credentials selectively as to not get caught, or they will get caught quickly, and the certs will be blacklisted. Either way, the long term risks are negligible, as long as all CAs migrate from MD5 immediately, or take other precautionary measures, such as using a random certificate ID instead of a sequential one.

And for those CAs that don’t take mitigating steps immediately, the operating systems and browsers of the world should move to blacklist them ASAP.

Right now, the only CA that seems to consistently sign using only MD5 (signing with both also thwarts this attack) is RapidSSL/FreeSSL (FreeSSL is owned by RapidSSL, and is used for trial certs). Who knows why these guys have not migrated away from MD5. But assuming they do it soon, there is little to worry about.

* John Viega is CEO of Stonewall Software and author of several security books including the classic Building Secure Software (Addison Wesley, 2001), and the forthcoming Myths of Security (O’Reilly, 2009). Follow him on Twitter.

Source: zdnet]