Posts Tagged: chrome


12
Jan 13

What You Need to Know About the Java Exploit

On Thursday, the world learned that attackers were breaking into computers using a previously undocumented security hole in Java, a program that is installed on hundreds of millions of computers worldwide. This post aims to answer some of the most frequently asked questions about the vulnerability, and to outline simple steps that users can take to protect themselves.

Update, Jan. 13, 8:14 p.m. ET: Oracle just released a patch to fix this vulnerability. Read more here.

3bjavaQ: What is Java, anyway?
A: Java is a programming language and computing platform that powers programs including utilities, games, and business applications. According to Java maker Oracle Corp., Java runs on more than 850 million personal computers worldwide, and on billions of devices worldwide, including mobile and TV devices. It is required by some Web sites that use it to run interactive games and applications.

Q: So what is all the fuss about?
A: Researchers have discovered that cybercrooks are attacking a previously unknown security hole in Java 7 that can be used to seize control over a computer if a user visits a compromised or malicious Web site.

Q: Yikes. How do I protect my computer?
A: The version of Java that runs on most consumer PCs includes a browser plug-in. According to researchers at Carnegie Mellon University‘s CERT, unplugging the Java plugin from the browser essentially prevents exploitation of the vulnerability. Not long ago, disconnecting Java from the browser was not straightforward, but with the release of the latest version of Java 7 — Update 10 — Oracle included a very simple method for removing Java from the browser. You can find their instructions for doing this here.

Q: How do I know if I have Java installed, and if so, which version?
A: The simplest way is to visit this link and click the “Do I have Java” link, just below the big red “Download Java” button.

Q: I’m using Java 6. Does that mean I don’t have to worry about this?
A: There have been conflicting findings on this front. The description of this bug at the National Vulnerability Database (NVD), for example, states that the vulnerability is present in Java versions going back several years, including version 4 and 5. Analysts at vulnerability research firm Immunity say the bug could impact Java 6 and possibly earlier versions. But Will Dormann, a security expert who’s been examining this flaw closely for CERT, said the NVD’s advisory is incorrect: CERT maintains that this vulnerability stems from a component that Oracle introduced  with Java 7. Dormann points to a detailed technical analysis of the Java flaw by Adam Gowdiak of Security Explorations, a security research team that has alerted Java maker Oracle about a large number of flaws in Java. Gowdiak says Oracle tried to fix this particular flaw in a previous update but failed to address it completely.

Either way, it’s important not to get too hung up on which versions are affected, as this could become a moving target. Also, a new zero-day flaw is discovered in Java several times a year. That’s why I’ve urged readers to either uninstall Java completely or unplug it from the browser no matter what version you’re using.

Q: A site I use often requires the Java plugin to be enabled. What should I do?
A: You could downgrade to Java 6, but that is not a very good solution. Oracle will stop supporting Java 6 at the end of February 2013, and will soon be transitioning Java 6 users to Java 7 anyway. If you need Java for specific Web sites, a better solution is to adopt a two-browser approach. If you normally browse the Web with Firefox, for example, consider disabling the Java plugin in Firefox, and then using an alternative browser (Chrome, IE9, Safari, etc.) with Java enabled to browse only the site(s) that require(s) it.

Q: I am using a Mac, so I should be okay, right?
A: Not exactly. Experts have found that this flaw in Java 7 can be exploited to foist malware on Mac and Linux systems, in addition to Microsoft Windows machines. Java is made to run programs across multiple platforms, which makes it especially dangerous when new flaws in it are discovered. For instance, the Flashback worm that infected more than 600,000 Macs wiggled into OS X systems via a Java flaw. Oracle’s instructions include advice on how to unplug Java from Safari. I should note that Apple has not provided a version of Java for OS X beyond 6, but users can still download and install Java 7 on Mac systems. However, it appears that in response to this threat, Apple has taken steps to block Java from running on OS X systems.

Q: I don’t browse random sites or visit dodgy porn sites, so I shouldn’t have to worry about this, correct?
A: Wrong. This vulnerability is mainly being exploited by exploit packs, which are crimeware tools made to be stitched into Web sites so that when visitors come to the site with vulnerable/outdated browser plugins (like this Java bug), the site can silently install malware on the visitor’s PC. Exploit packs can be just as easily stitched into porn sites as they can be inserted into legitimate, hacked Web sites. All it takes is for the attackers to be able to insert one line of code into a compromised Web site.

Q: I’ve read in several places that this is the first time that the U.S. government has urged computer users to remove or wholesale avoid using a particular piece of software because of a widespread threat. Is this true?
A: Not really. During previous high-alert situations, CERT has advised Windows users to avoid using Internet Explorer. In this case, CERT is not really recommending that users uninstall Java: just that users unplug Java from their Web browser.

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8
Jan 13

Adobe, Microsoft Ship Critical Security Updates

Adobe and Microsoft today separately issued updates to fix critical security vulnerabilities in their products. Adobe pushed out fixes for security issues in Acrobat, Adobe Reader and its Flash Player plugin. Microsoft released seven patches addressing at least a dozen security holes in Windows and other software, although it failed to issue an official patch for a dangerous flaw in its Internet Explorer Web browser that attackers are now actively exploiting.

Two of the patches that Microsoft issued today earned a “critical” rating, signifying that these vulnerabilities could be exploited to fully compromise vulnerable Windows systems without any help from users. Microsoft called special attention to two critical bugs in its XML Core Services component; the company said it is likely that malware or miscreants will figure out a way to exploit these flaws in active attacks sometime within the next 30 days.

Unfortunately, Microsoft did not offer an official fix for a critical Windows flaw that malware and miscreants are already exploiting. In late December, Microsoft acknowledged that attackers were using a previously undocumented security hole in Internet Explorer versions 6 through 8 to break into Windows PCs. Microsoft later issued a stopgap “FixIt” tool to help lessen the vulnerability on affected systems, but researchers last week demonstrated that the FixIt tool only blocked some methods of attacking the flaw, leaving other ways unguarded. Meanwhile, a working copy of the exploit has been folded into Metasploit, a free penetration testing tool.

Wolfgang Kandek, chief technology officer at vulnerability management firm Qualys, said the zero-day IE vulnerability affects 90% of the IE install base at this time.

“Microsoft is not providing a patch today, though they have provided a Fix-It for the issue,” Kandek wrote in a blog post. “The vulnerability should be tracked closely, as a large percentage of enterprises still run the affected versions.”

Users who wish to continue browsing the Web with IE should upgrade to IE9 if possible (IE10 on Windows 8 also is not vulnerable). Users still on Windows XP will not be able to update to IE9, but may be able to derive some protection from the FixIt tool and by using Microsoft’s EMET tool. XP users may be better off, however, browsing with Firefox or Chrome with some type of script blocking and/or sandbox in place. More information on how to use EMET and script blocking options is available in my Tools for a Safer PC primer. More details about today’s updates from Microsoft can be found at the Microsoft Security Response Center blog and in the security bulletin summaries for each patch.

The Adobe Flash patch fixes at least one critical vulnerability in the media player plugin. Updates are available for all supported versions of Flash, including for Windows, Mac, Linux and Android. See the chart below for the latest version number broken down by operating system.

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18
Sep 12

Internet Explorer Users: Please Read This

Microsoft is urging Windows users who browse the Web with Internet Explorer to use a free tool called EMET to block attacks against a newly-discovered and unpatched critical security hole in IE versions 7, 8 and 9. But some experts say that advice falls short, and that users can better protect themselves by surfing with an alternative browser until Microsoft issues a proper patch for the vulnerability.

The application page of EMET.

EMET, short for the Enhanced Mitigation Experience Toolkit, is a tool that can help Windows users beef up the security of commonly used applications, whether they are made by a third-party vendor or by Microsoft. EMET allows users to force applications to use one or both of two key security defenses built into Windows Vista and Windows 7 — Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP).

Put very simply, DEP is designed to make it harder to exploit security vulnerabilities on Windows, and ASLR makes it more difficult for exploits and malware to find the specific places in a system’s memory that they need to do their dirty work.

Before I get into the how-tos on EMET, a few caveats. EMET is a great layer of security that Windows users can and should use to enhance the security of applications. But EMET may not block the exploit code now publicly available through the Metasploit framework. In fact, Tod Beardlsey, an engineering manager with Rapid7, the security firm that manages Metasploit, told The Associated Press that EMET does not appear to be completely effective against this exploit.

I asked Metasploit founder HD Moore what he thought was the best way to block this exploit, and he pointed out that the exploit available through Metasploit requires the presence of Java on the host machine in order to execute properly on IE 8/9 on Windows 7 and Vista systems (the exploit works fine without Java against IE7 on XP/Vista and IE8 on XP). Obviously, while the lack of Java on a Windows machine may not prevent other exploits against this flaw, it is a great first start. I have consistently urged computer users of all stripes to uninstall Java if they have no specific use for it.

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29
Aug 12

Researchers: Java Zero-Day Leveraged Two Flaws

New analysis of a zero-day Java exploit that surfaced last week indicates that it takes advantage of not one but two previously unknown vulnerabilities in the widely-used software. The latest figures suggest that these vulnerabilities have exposed more than a billion users to attack.

Esteban Guillardoy, a developer at the security firm Immunity Inc., said the underlying vulnerability has been around since July 28, 2011.

“There are 2 different zero-day vulnerabilities used in this exploit,” Guillardoy wrote in a lengthy analysis of the exploit. “The beauty of this bug class is that it provides 100% reliability and is multi-platform. Hence this will shortly become the penetration test Swiss knife for the next couple of years (as did its older brother CVE-2008-5353).”

ONE BILLION USERS AT RISK?

How many systems are vulnerable? Oracle Corp., which maintains Java, claims that more than 3 billion devices run Java. But how many of those systems run some version of Java 7 (all versions of Java 7 are vulnerable; this flaw does not exist in Java 6 versions).

To get an idea, I asked Secunia, whose Personal Software Inspector program runs on millions of PCs. Secunia said that out of a random sampling of 10,000 PSI users, 34.2 percent had some version of Java 7 installed. In the same data set, 56.4 percent of users had an update of Java 6 installed. Assuming that Secunia’s 10,000 user sample is representative of the larger population of computer users, more than a billion devices could be vulnerable to attack via this exploit.

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5
Jul 12

New Java Exploit to Debut in BlackHole Exploit Kits

Malicious computer code that leverages a newly-patched security flaw in Oracle’s Java software is set to be deployed later this week to cybercriminal operations powered by the BlackHole exploit pack. The addition of a new weapon to this malware arsenal will almost certainly lead to a spike in compromised PCs, as more than 3 billion devices run Java and many of these installations are months out of date.

I first learned about the new exploit from a KrebsOnSecurity reader named Dean who works in incident response for a financial firm. Dean was trying to trace the source of an infected computer in his network; he discovered the culprit appeared to be a malicious “.jar” file. A scan of the jar file at Virustotal.com showed that it was detected by just one antivirus product (Avira), which flagged it as “Java/Dldr.Lamar.BD”. The description of that threat says it targets a Javas vulnerability tagged as CVE-2012-1723, a critical bug fixed in Java 6 Update 33 and Java 7 Update 5.

The attack may be related to an exploit published for CVE-2012-1723 in mid-June by Michael ‘mihi’ Schierl. But according to the current vendor of the BlackHole exploit pack, the exact exploit for this vulnerability has only been shared and used privately to date. Reached via instant message, the BlackHole author said the new Java attack will be rolled into a software update to be made available on July 8 to all paying and licensed users of BlackHole.

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4
May 12

Critical Flash Update Fixes Zero-day Flaw

Adobe Systems Inc. today issued a security update to its Flash Player software. The company stressed that the update fixes a critical vulnerability that malicious actors have been using in targeted attacks.

Adobe classifies a security flaw as critical if it can be used to break into vulnerable machines without any help from users. The company said the vulnerability (CVE-2012-0779) fixed in the version released today has been exploited in targeted attacks designed to trick the user into clicking on a malicious file delivered in an email message, and that the exploit used in the attacks seen so far target Flash Player on Internet Explorer for Windows only.

Nevertheless, there are updates available for Flash Player versions designed for all operating systems that Adobe supports, including Mac, Linux and Android devices.

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5
Jun 11

Flash Player Patch Fixes Zero-Day Flaw

Adobe released an emergency security update today to fix a vulnerability that the company warned is being actively exploited in targeted attacks designed to trick the user into clicking on a malicious link delivered in an email message.

The vulnerability — a cross-site scripting bug that could be used to take actions on a user’s behalf on any Web site or Webmail provider, exists in Flash Player version 10.3.181.16 and earlier for Windows, Macintosh, Linux and Solaris. Adobe recommends users update to version 10.3.181.22 (on Internet Explorer, the latest, patched version is 10.3.181.23).  To find out what version of Flash you have, go here.

Google appears to have already pushed out an update that fixes this flaw in Chrome. Adobe says it will ship an update to fix this flaw on Android sometime this week.

Adobe said it is still investigating whether this is exploitable in Adobe Reader and Acrobat X (10.0.2) and earlier 10.x and 9.x versions of Adobe Reader and Acrobat for Windows and Macintosh operating systems, and that it is not aware of any attacks targeting Adobe Reader or Acrobat in the wild.

Remember that if you use Internet Explorer in addition to other browsers, you will need to apply this update twice: Once to install the Flash Active X plugin for IE, and again to update other browsers, such as Firefox and Opera. Updates are available by browsing with the appropriate browser to the Flash Player Download Center. Bear in mind that updating via the Download Center involves installing Adobe’s Download Manager, which may try to foist additional software. If you’d prefer to update manually, the direct installers for Windows are available at this link. If you run into problems installing this update, you’ll want to uninstall previous versions of Flash Player and then try again.


25
May 11

Blocking JavaScript in the Browser

Most Web sites use JavaScript, a powerful scripting language that helps make sites interactive. Unfortunately, a huge percentage of Web-based attacks use JavaScript tricks to foist malicious software and exploits onto site visitors. To protect yourself, it is critically important to have an easy method of selecting which sites should be allowed to run JavaScript in the browser.

It is true that selectively allowing JavaScript on known, “safe” sites won’t block all malicious scripting attacks: Even legitimate sites sometimes end up running malicious code when scammers figure out ways to sneak tainted, bogus ads into the major online ad networks. But disallowing JavaScript by default and selectively enabling it for specific sites remains a much safer option than letting all sites run JavaScript unrestricted all the time.

Firefox has many extensions and add-ons that make surfing the Web a safer experience. One extension that I have found indispensable is NoScript. This extension lets the user decide which sites should be allowed to run JavaScript, including Flash Player content. Users can choose to allow specific exceptions either permanently or for a single browsing session.

The NoScript extension makes it easy to place or remove these restrictions on a site-by-site basis, but a novice user may need some practice to get the hang of doing this smoothly. For instance, it’s not uncommon when you’re shopping online to come across a site that won’t let you submit data without fully allowing JavaScript. Then, when you enable scripting so that you can submit your address and payment information, the page often will reload and clear all of the form data you’ve already supplied, forcing you to start over. Also, many sites host content from multiple third-party sites, and users who prefer to selectively enable scripts may find it challenging to discover which scripts need to be enabled for the site to work properly.

Chrome also includes similar script- and Flash blocking functionality that seems designed to minimize some of these challenges by providing fewer options. If you tell Chrome to block JavaScript on all sites by default, when you browse to a site that uses JavaScript, the upper right corner of the browser displays a box with a red “X” through it. If you click that and select “Always allow JavaScript on [site name]” it will permanently enable JavaScript for that site, but it doesn’t give you the option to block third-party JavaScript content on the site as Noscript does. In my testing, I had to manually refresh the page before Chrome allowed scripting on a site that I’d just whitelisted.

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13
May 11

Critical Flash Player Update Plugs 11 Holes

Adobe has released another batch of security updates for its ubiquitous Flash Player software. This “critical” patch fixes at least 11 vulnerabilities, including one that reports suggest is being exploited in targeted email attacks.

In the advisory that accompanies this update, Adobe said “there are reports of malware attempting to exploit one of the vulnerabilities, CVE-2011-0627, in the wild via a Flash (.swf) file embedded in a Microsoft Word (.doc) or Microsoft Excel (.xls) file delivered as an email attachment targeting the Windows platform. However, to date, Adobe has not obtained a sample that successfully completes an attack.”

The vulnerabilities exist in Flash versions 10.2.159.1 and earlier for Windows, Mac, Linux and Solaris. To learn which version of Flash you have, visit this link. The new version for most platforms is 10.3.181.14; Android users should upgrade to Flash Player 10.3.185.21 available by browsing to the Android Marketplace on an Android phone; Google appears to have updated Chrome users automatically with this version of Flash back on May 6 (Chrome versions 11.0.696.68 and later have the newest Flash version).

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2
May 11

‘Weyland-Yutani’ Crime Kit Targets Macs for Bots

A new crimeware kit for sale on the criminal underground makes it a simple point-and-click exercise to develop malicious software designed to turn Mac OSX computers into remotely controllable zombie bots. According to the vendor of this kit, it is somewhat interchangeable with existing crimeware kits made to attack Windows-based PCs.

The Mac malware builder in action.

KrebsOnSecurity has spilled a great deal of digital ink covering the damage wrought by ZeuS and SpyEye, probably the most popular crimeware kits built for Windows. A crimeware kit is a do-it-yourself package of tools that allow users to create custom versions of a malicious software strain capable of turning machines into bots that can be remotely controlled and harvested of financial and personal data. The bot code, generated by the crimeware kit’s “builder” component, typically is distributed via social engineering attacks in email and social networking sites, or is foisted by an exploit pack like Eleonore or Blackhole, which use hacked Web sites and browser flaws to quietly install the malware. Crimeware kits also come with a Web-based administration panel that allows the customer to manage and harvest data from infected PCs.

Crimekit makers have focused almost exclusively on the Windows platform, but today Danish IT security firm CSIS Security Group blogged about a new kit named the Weyland-Yutani BOT that is being marketed as the first of its kind to attack the Mac OS X platform.

The seller of this crimeware kit claims his product supports form-grabbing in Firefox and Chrome, and says he plans to develop a Linux version and one for the iPad in the months ahead. The price? $1,000, with payment accepted only through virtual currencies Liberty Reserve or WebMoney.

The CSIS blog post contains a single screen shot of this kit’s bot builder, and references a demo video but doesn’t show it. I wanted to learn more about this kit, and so contacted the seller via a Russian language forum where he was advertising his wares.

The author said he is holding off on including Safari form-grabbing capability for now, complaining that there are “too many problems in that browser.” Still, he was kind enough to share a copy of a video that shows the kit’s builder and admin panel in action. Click the video link below to check that out.

ZeuS and SpyEye are popular in part because they support a variety of so-called “Web injects,” third-party plug-ins that let botmasters manipulate the content that victims see in their Web browsers. The most popular Web injects are designed to slightly alter the composition of various online banking Web sites in a bid to trick the victim customer into supplying additional identifying information that can be used later on to more fully compromise or hijack the account. According to the author, Web injects developed for ZeuS and SpyEye also are interchangeable with this Mac crimekit. “They need to be formatted and tagged, but yes, you can use Zeus injects with this bot,” he told me in an instant message conversation.

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