Posts Tagged: Google Chrome


8
Mar 18

Look-Alike Domains and Visual Confusion

How good are you at telling the difference between domain names you know and trust and impostor or look-alike domains? The answer may depend on how familiar you are with the nuances of internationalized domain names (IDNs), as well as which browser or Web application you’re using.

For example, how does your browser interpret the following domain? I’ll give you a hint: Despite appearances, it is most certainly not the actual domain for software firm CA Technologies (formerly Computer Associates Intl Inc.), which owns the original ca.com domain name:

https://www.са.com/

Go ahead and click on the link above or cut-and-paste it into a browser address bar. If you’re using Google Chrome, Apple’s Safari, or some recent version of Microsoft‘s Internet Explorer or Edge browsers, you should notice that the address converts to “xn--80a7a.com.” This is called “punycode,” and it allows browsers to render domains with non-Latin alphabets like Cyrillic and Ukrainian.

Below is what it looks like in Edge on Windows 10; Google Chrome renders it much the same way. Notice what’s in the address bar (ignore the “fake site” and “Welcome to…” text, which was added as a courtesy by the person who registered this domain):

The domain https://www.са.com/ as rendered by Microsoft Edge on Windows 10. The rest of the text in the image (beginning with “Welcome to a site…”) was added by the person who registered this test domain, not the browser.

IE, Edge, Chrome and Safari all will convert https://www.са.com/ into its punycode output (xn--80a7a.com), in part to warn visitors about any confusion over look-alike domains registered in other languages. But if you load that domain in Mozilla Firefox and look at the address bar, you’ll notice there’s no warning of possible danger ahead. It just looks like it’s loading the real ca.com:

What the fake ca.com domain looks like when loaded in Mozilla Firefox. A browser certificate ordered from Comodo allows it to include the green lock (https://) in the address bar, adding legitimacy to the look-alike domain. The rest of the text in the image (beginning with “Welcome to a site…”) was added by the person who registered this test domain, not the browser. Click to enlarge.

The domain “xn--80a7a.com” pictured in the first screenshot above is punycode for the Ukrainian letters for “s” (which is represented by the character “c” in Russian and Ukrainian), as well as an identical Ukrainian “a”.

It was registered by Alex Holden, founder of Milwaukee, Wis.-based Hold Security Inc. Holden’s been experimenting with how the different browsers handle punycodes in the browser and via email. Holden grew up in what was then the Soviet Union and speaks both Russian and Ukrainian, and he’s been playing with Cyrillic letters to spell English words in domain names.

Letters like A and O look exactly the same and the only difference is their Unicode value. There are more than 136,000 Unicode characters used to represent letters and symbols in 139 modern and historic scripts, so there’s a ton of room for look-alike or malicious/fake domains.

For example, “a” in Latin is the Unicode value “0061” and in Cyrillic is “0430.”  To a human, the graphical representation for both looks the same, but for a computer there is a huge difference. Internationalized domain names (IDNs) allow domain names to be registered in non-Latin letters (RFC 3492), provided the domain is all in the same language; trying to mix two different IDNs in the same name causes the domain registries to reject the registration attempt.

So, in the Cyrillic alphabet (Russian/Ukrainian), we can spell АТТ, УАНОО, ХВОХ, and so on. As you can imagine, the potential opportunity for impersonation and abuse are great with IDNs. Here’s a snippet from a larger chart Holden put together showing some of the more common ways that IDNs can be made to look like established, recognizable domains:

Image: Hold Security.

Holden also was able to register a valid SSL encryption certificate for https://www.са.com from Comodo.com, which would only add legitimacy to the domain were it to be used in phishing attacks against CA customers by bad guys, for example. Continue reading →


13
Feb 18

Microsoft Patch Tuesday, February 2018 Edition

Microsoft today released a bevy of security updates to tackle more than 50 serious weaknesses in Windows, Internet Explorer/Edge, Microsoft Office and Adobe Flash Player, among other products. A good number of the patches issued today ship with Microsoft’s “critical” rating, meaning the problems they fix could be exploited remotely by miscreants or malware to seize complete control over vulnerable systems — with little or no help from users.

February’s Patch Tuesday batch includes fixes for at least 55 security holes. Some of the scarier bugs include vulnerabilities in Microsoft Outlook, Edge and Office that could let bad guys or bad code into your Windows system just by getting you to click on a booby trapped link, document or visit a compromised/hacked Web page.

As per usual, the SANS Internet Storm Center has a handy rundown on the individual flaws, neatly indexing them by severity rating, exploitability and whether the problems have been publicly disclosed or exploited. Continue reading →


2
Feb 18

Attackers Exploiting Unpatched Flaw in Flash

Adobe warned on Thursday that attackers are exploiting a previously unknown security hole in its Flash Player software to break into Microsoft Windows computers. Adobe said it plans to issue a fix for the flaw in the next few days, but now might be a good time to check your exposure to this still-ubiquitous program and harden your defenses.

Adobe said a critical vulnerability (CVE-2018-4878) exists in Adobe Flash Player 28.0.0.137 and earlier versions. Successful exploitation could allow an attacker to take control of the affected system.

The software company warns that an exploit for the flaw is being used in the wild, and that so far the attacks leverage Microsoft Office documents with embedded malicious Flash content. Adobe said it plans to address this vulnerability in a release planned for the week of February 5.

According to Adobe’s advisory, beginning with Flash Player 27, administrators have the ability to change Flash Player’s behavior when running on Internet Explorer on Windows 7 and below by prompting the user before playing Flash content. A guide on how to do that is here (PDF). Administrators may also consider implementing Protected View for Office. Protected View opens a file marked as potentially unsafe in Read-only mode.

Continue reading →


7
Jul 15

Adobe to Patch Hacking Team’s Flash Zero-Day

Adobe Systems Inc. says its plans to issue a patch on Wednesday to fix a zero-day vulnerability in its Flash Player software that is reportedly being exploited in active attacks. The flaw was disclosed publicly over the weekend after hackers broke into and posted online hundreds of gigabytes of data from Hacking Team, a controversial Italian company that’s long been accused of helping repressive regimes spy on dissident groups.

A knowledge base file stolen from Hacking Team explaining how to use the company's zero-day Flash exploit.

A knowledge base file stolen from Hacking Team explaining how to use a Flash exploit developed by the company.

In an advisory published today, Adobe said “a critical vulnerability (CVE-2015-5119) has been identified in Adobe Flash Player 18.0.0.194 and earlier versions for Windows, Macintosh and Linux. Successful exploitation could cause a crash and potentially allow an attacker to take control of the affected system.”

Update, July 8, 12:13 p.m. ET: The patch is now available in Flash Player 18.0.0.203 for Windows and Mac systems. See this advisory for more information and for links to downloads.

Original story:

Several reports on Twitter suggested the exploit could be used to bypass Google Chrome‘s protective “sandbox” technology, a security feature that forces the program to run in a heightened security mode designed to block attacks that target vulnerabilities in Flash. A spokesperson for Google confirmed that attackers could evade the Chrome sandbox by using the Flash exploit in tandem with another Windows vulnerability that appears to be unpatched at the moment. Google also says its already in the process of pushing the Flash fix out to Chrome users.

The Flash flaw was uncovered after Hacking Team’s proprietary information was posted online by hacktivists seeking to disprove the company’s claims that it does not work with repressive regimes (the leaked data suggests that Hacking Team has contracted to develop exploits for a variety of countries, including Egypt, Lebanon, Ethiopia, Sudan and Thailand). Included in the cache are several exploits for unpatched flaws, including apparently a Windows vulnerability. Continue reading →


14
Apr 15

Critical Updates for Windows, Flash, Java

Get your patch chops on people, because chances are you’re running software from Microsoft, Adobe or Oracle that received critical security updates today. Adobe released a Flash Player update to fix at least 22 flaws, including one flaw that is being actively exploited. Microsoft pushed out 11 update bundles to fix more than two dozen bugs in Windows and associated software, including one that was publicly disclosed this month. And Oracle has an update for its Java software that addresses at least 15 flaws, all of which are exploitable remotely without any authentication.

brokenflash-aAdobe’s patch includes a fix for a zero-day bug (CVE-2015-3043) that the company warns is already being exploited. Users of the Adobe Flash Player for Windows and Macintosh should update to Adobe Flash Player 17.0.0.169 (the current versions other OSes is listed in the chart below).

If you’re unsure whether your browser has Flash installed or what version it may be running, browse to this link. Adobe Flash Player installed with Google Chrome, as well as Internet Explorer on Windows 8.x, should automatically update to version 17.0.0.169.

Google has an update available for Chrome that fixes a slew of flaws, and I assume it includes this Flash update, although the Flash checker pages only report that I now have version 17.0.0 installed after applying the Chrome update and restarting (the Flash update released last month put that version at 17.0.0.134, so this is not particularly helpful). To force the installation of an available update, click the triple bar icon to the right of the address bar, select “About Google” Chrome, click the apply update button and restart the browser.

The most recent versions of Flash should be available from the Flash home page, but beware potentially unwanted add-ons, like McAfee Security Scan. To avoid this, uncheck the pre-checked box before downloading, or grab your OS-specific Flash download from here. Windows users who browse the Web with anything other than Internet Explorer may need to apply this patch twice, once with IE and again using the alternative browser (Firefox, Opera, e.g.).

brokenwindowsMicrosoft has released 11 security bulletins this month, four of which are marked “critical,” meaning attackers or malware can exploit them to break into vulnerable systems with no help from users, save for perhaps visiting a booby-trapped or malicious Web site. The Microsoft patches fix flaws in Windows, Internet Explorer (IE), Office, and .NET

The critical updates apply to two Windows bugs, IE, and Office. .NET updates have a history of taking forever to apply and introducing issues when applied with other patches, so I’d suggest Windows users apply all other updates, restart and then install the .NET update (if available for your system). Continue reading →


15
May 14

The Mad, Mad Dash to Update Flash

An analysis of how quickly different browser users patch Adobe Flash vulnerabilities shows a marked variation among browser makers. The data suggest that Google Chrome and Mozilla Firefox users tend to get Flash updates relatively quickly, while many users on Microsoft’s Internet Explorer browser consistently lag behind.

The information comes from ThreatMetrix, a company that helps retailers and financial institutions detect and block patterns of online fraud. ThreatMetrix Chief Technology Officer Andreas Baumhof looked back over the past five months across 10,000+ sites the company serves, to see how quickly visitors were updating to the latest versions of Flash.

Baumhof measured the rates of update adoption for these six Flash patches:

Jan 14, 2014 – APSB14-02 Security updates available for Adobe Flash Player (2 critical vulnerabilities)

Feb 4, 2014 – APSB14-04 Security updates available for Adobe Flash Player (2 critical flaws, including 1 zero-day)

Feb 20, 2014 – APSB14-07 Security updates available for Adobe Flash Player (1 zero-day)

Mar 11, 2014 – APSB14-08 Security updates available for Adobe Flash Player (2 critical vulnerabilities)

Apr 8, 2014, – APSB14-09 Security updates available for Adobe Flash Player (4 critical vulnerabilities)

Apr 28, 2014 – APSB14-13 Security updates available for Adobe Flash Player (1 zero-day)

Overall, Google Chrome users were protected the fastest. According to Baumhof, Chrome usually takes just a few days to push the latest update out to 90 percent of users. Chrome pioneered auto-updates for Flash several years ago, with Firefox and newer versions of IE both following suit in recent years.

The adoption rate, broken down by browser type, of the last six Adobe Flash updates.

The adoption rate, broken down by browser type, of the last six Adobe Flash updates.

Interestingly, the data show that IE users tend to receive updates at a considerably slower clip (although there are a few times in which IE surpasses Firefox users in adoption of the latest Flash updates).  This probably has to do with the way Flash is updated on IE, and the legacy versions of IE that are still out there. Flash seems to have more of a seamless auto-update process on IE 10 and 11 on Windows 8 and above, and more of a manual one on earlier versions of the browser and operating system.

Another explanation for IE’s performance here is that it is commonly used in business environments, which tend to take a few days at least to test patches before rolling them out in a coordinated fashion across the enterprise along with the rest of the Patch Tuesday updates. Continue reading →


8
Jul 13

Styx Exploit Pack: Domo Arigato, PC Roboto

Not long ago, miscreants who wanted to buy an exploit kit — automated software that helps booby-trap hacked sites to deploy malicious code  — had to be fairly well-connected, or at least have access to semi-private underground forums. These days, some exploit kit makers are brazenly advertising and offering their services out in the open, marketing their wares as browser vulnerability “stress-test platforms.”

Styx Pack victims, by browser and OS version.

Styx Pack victims, by browser and OS version.

Aptly named after the river in Greek mythology that separates mere mortals from the underworld, the Styx exploit pack is a high-end software package that is made for the underground but marketed and serviced at the public styx-crypt[dot]com. The purveyors of this malware-as-a-service also have made a 24 hour virtual help desk available to paying customers.

Styx customers might expect such niceties for the $3,000 price tag that accompanies this kit. A source with access to one Styx kit exploit panel that was apparently licensed by a team of bad guys shared a glimpse into their operations and the workings of this relatively slick crimeware offering.

The Styx panel I examined is set up for use by a dozen separate user accounts, each of which appears to be leveraging the pack to load malware components that target different moneymaking schemes. The account named “admin,” for example, is spreading an executable file that tries to install the Reveton ransomware.

Other user accounts appear to be targeting victims in specific countries. For example, the user accounts “IT” and “IT2” are pushing variants of the ZeuS banking trojan, and according to this Styx panel’s statistics page, Italy was by far the largest source of traffic to the malicious domains used by these two accounts. Additional apparently country-focused accounts included “NL,” AUSS,” and “Adultamer” (“amer” is a derisive Russian slur used to describe Americans).

ZeuS Trojan variants targeted at Italian victims were detected by fewer than 5 out 17 antivirus tools.

ZeuS Trojan variants targeted at Italian victims were detected by fewer than 5 out 17 antivirus tools.

An exploit kit — also called an “exploit pack” (Styx is marketed as “Styx Pack”) is a software toolkit that gets injected into hacked or malicious sites, allowing the attacker to foist a kitchen sink full of browser exploits on visitors. Those visiting such sites with outdated browser plugins may have malware silently installed.

Unlike other kits, Styx doesn’t give a detailed breakdown of the exploits used in the panel. Rather, the panel I looked at referred to its bundled exploits by simple two-digit numbers. This particular Styx installation used just four browser exploits, all but one of which targets recent vulnerabilities in Java. The kit referred to each exploit merely by the numbers 11, 12, 13 and 32.

According to the considerable legwork done by Kafeine, a security blogger who digs deeply into exploit kit activity, Styx Kit exploit #11 is likely to be CVE-2013-1493, a critical flaw in a Java browser plugin that Java maker Oracle fixed with an emergency patch in March 2013. Exploit 12 is almost certainly CVE-2013-2423, another critical Java bug that Oracle patched in April 2013. In an instant message chat, Kafeine says exploit #13 is probably CVE-2013-0422, a critical Java vulnerability that was patched in January 2013. The final exploit used by the kit I examined, number 32, maps to CVE-2011-3402, the same Microsoft Windows font flaw exploited by the Duqu Trojan.

The Styx stats page reports that the hacked and malicious sites used by this kit have been able to infect roughly one out of every 10 users who visited the sites. This particular Styx installation was set up on June 24, 2013, and since that time it has infected approximately 13,300 Windows PCs — all via just those  four vulnerabilities (but mostly the Java bugs).

Continue reading →


12
Mar 13

Critical Updates for Windows, Adobe Flash, Air

Microsoft and Adobe each released patches today to plug critical security holes in their products. Microsoft issued seven update bundles to address at least 19 20 vulnerabilities in Windows and related software. Adobe released the fourth security update in nearly as many weeks for its Flash Player software, as well as a fix for Adobe AIR.

winiconMicrosoft today began pushing out seven security patches, four of them rated “critical,” meaning the flaws they fix could be used by malware or bad guys to break into unpatched systems with little or no help from users. The critical patches address bugs in Windows, Internet Explorer, Microsoft Silverlight, Microsoft Office and Microsoft SharePoint. Updates are available for Windows XP, Vista, Windows 7, Windows 8, Windows Server 2003, 2008 and 2012.

More information on the Microsoft patches is available at the Microsoft security response center blog, which also discusses some changes to the way security updates are applied to apps available through the Windows Store.

Continue reading →


11
Mar 13

Help Keep Threats at Bay With ‘Click-to-Play’

Muzzling buggy and insecure Web browser plugins like Java and Flash goes a long way toward blocking attacks from drive-by downloads and hacked or malicious Web sites. But leaving them entirely unplugged from the browser is not always practical, particularly with Flash, which is used on a majority of sites. Fortunately for many users, there is a relatively simple and effective alternative: Click-to-Play.

c2pGCClick-to-Play is a feature built into both Google Chrome, Mozilla Firefox and Opera (and available via add-ons in Safari) that blocks plugin activity by default, replacing the plugin content on the page with a blank box. Users who wish to view the blocked content need only click the boxes to enable the Flash or Java content inside of them.

To enable click-to-play on Chrome: From the main menu, click Settings, then in the search box type “click to play,” and click the highlighted box labeled “content settings.” In content settings, scroll down to the “plug-ins” section, and change the default from “run automatically” to “click to play”. To enable exceptions so that certain sites (krebsonsecurity.com?) are allowed to load Flash and other content by default, click the “manage exceptions” box. Alternatively, this can be done in Chrome through the address bar: when you browse to a site that has content blocked by the click-to-play feature, an icon will appear on the far right side of the address bar that allows you to add an exception for the current site.

c2pFFTo enable click-to-play in Firefox: Open a browser window and type “about:config” without the quotes. In the search box at the top of the resulting window, paste the follow “plugins.click_to_play”, again without the quotes. Double click the entry that shows up so that its setting under the “value” column changes from “false” to “true” (hat tip to F-Secure.com for this advice). To enable per-site exceptions, look for the blue lego-like icon in the lefthand portion of the URL bar, and click it; click the “activate” button to enable plugins just for that session, or to make it permanent for that site, click the down arrow next to “activate all plugins” and select the “always activate plugins for this site” option.

Continue reading →


6
Nov 12

Adobe Ships Election Day Security Update for Flash

Adobe has released a critical security update for its Flash Player and Adobe AIR software that fixes at least seven dangerous vulnerabilities in these products. Updates are available for Windows, Mac, Linux and Android systems.

Today’s update, part of Adobe’s regularly scheduled patch cycle for Flash, brings Flash Player to version 11.5.502.110 on Windows and Mac systems (other OS users see graphic below). Adobe urges users to grab the latest updates from its Flash Player Download Center, but that option pushes junk add-ons like McAfee VirusScan. Instead, download the appropriate version for your system from Adobe’s Flash Player Distribution page. Most users can find out what version of Flash they have installed by visiting this link.

The Flash Player installed with Google Chrome should soon be automatically updated to the latest Google Chrome version, which will include Flash Player 11.5.31.2 for Windows, Macintosh and Linux. Note that Windows users who browse the Web with Internet Explorer and another browser will need to apply the Flash update twice, once using IE and again with the other browser. Internet Explorer 10 users on Windows 8 can grab the update via Windows Update or from Microsoft’s site, or wait for the browser to auto-update the plugin.

Adobe’s advisory about this update is available here, including links to update AIR if you have that installed. An Adobe spokesperson said the company is not aware of any active attacks or exploits in the wild for any of the issues patched in this release. Nevertheless, it’s a bad idea to delay Flash updates; the software’s ubiquity makes it a primary target of malware and miscreants alike.