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Mitigations Available for the DRAM Row Hammer Vulnerability

This blog post was authored by Troy Fridley and Omar Santos of Cisco PSIRT.

On Mar 9 2015, the Project Zero team at Google revealed findings from new research related to the known issue in the DDR3 Memory specification referred to as “Row Hammer”. Row Hammer is an industry-wide issue that has been discussed publicly since (at least) 2012.

The new research by Google shows that these types of errors can be introduced in a predictable manner. A proof-of-concept (POC) exploit that runs on the Linux operating system has been released. Successful exploitation leverages the predictability of these Row Hammer errors to modify memory of an affected device. An authenticated, local attacker with the ability to execute code on the affected system could elevate their privileges to that of a super user or “root” account. This is also known as Ring 0. Programs that run in Ring 0 can modify anything on the affected system. Read More »

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Ancient Mac Site Harbors Botnet that Exploits IE Vulnerability

This post was authored by Alex Chiu and Shaun Hurley.

Last month, Microsoft released a security bulletin to patch CVE-2014-6332, a vulnerability within Windows Object Linking and Embedding (OLE) that could result in remote code execution if a user views a maliciously crafted web page with Microsoft Internet Explorer. Since then, there have been several documented examples of attackers leveraging this vulnerability and attempting to compromise users. On November 26th, Talos began observing and blocking an attack disguised as a hidden iframe on a compromised domain to leverage this vulnerability and compromise Internet Explorer users.

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RIG Exploit Kit Strikes Oil

This post was co-authored by Levi Gundert with contributions from Emmanuel Tacheau and Joel Esler.

In the last month we have observed high levels of traffic consistent with the new “RIG” exploit kit (EK), as identified by Kahu Security. This new EK reportedly began being advertised on criminal forums in April, which coincides with when we first began blocking this traffic on April 24th. Whilst the release of a new EK is not uncommon, RIG’s appearance is significant in three ways. First, because of the sheer amount of traffic we are seeing – we have so far blocked requests to over 90 domains for more than 17% of our Cloud Web Security (CWS) customers. Second, because we have seen it being used to distribute “Cryptowall”, the latest ransomware to follow in the success of the now infamous “Cryptolocker”. And third, because it continues the trend of an increased reliance upon Silverlight in EKs which we have previously written about for both the Fiesta and Angler kits. Like these other kits, we have seen RIG using malvertising to perform a drive-by attack on visitors to high profile, legitimate websites. This accounts for the high amount of traffic we have seen in the last month. Read More »

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Angling for Silverlight Exploits

VRT / TRACThis post is co-authored by Andrew Tsonchev, Jaeson Schultz, Alex Chiu, Seth Hanford, Craig Williams, Steven Poulson, and Joel Esler. Special thanks to co-author Brandon Stultz for the exploit reverse engineering. 

Silverlight exploits are the drive-by flavor of the month. Exploit Kit (EK) owners are adding Silverlight to their update releases, and since April 23rd we have observed substantial traffic (often from Malvertising) being driven to Angler instances partially using Silverlight exploits. In fact in this particular Angler campaign, the attack is more specifically targeted at Flash and Silverlight vulnerabilities and though Java is available and an included reference in the original attack landing pages, it’s never triggered.

Rise in Angler Attacks

HTTP requests for a specific Angler Exploit Kit campaign

Exploit Content Type

Angler exploit content types delivered to victims, application/x-gzip (Java) is notably absent


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Year-Long Exploit Pack Traffic Campaign Surges After Leveraging CDN

TRACThis post is coauthored by Andrew Tsonchev.

Anyone can purchase an exploit pack (EP) license or rent time on an existing EP server. The challenge for threat actors is to redirect unsuspecting web browsing victims by force to the exploit landing page with sustained frequency. Naturally, like most criminal services in the underground, the dark art of traffic generation is a niche specialty that must be purchased to ensure drive-by campaign success. For the past year we have been tracking a threat actor (group) that compromises legitimate websites and redirects victims to EP landing pages. Over the past three months we observed the same actor using malvertising – leveraging content delivery networks (CDNs) to facilitate increased victim redirection – as part of larger exploit pack campaigns. Read More »

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