This blog was authored by Ben Baker, Edmund Brumaghin, and Jonah Samost.
GozNym is the combination of features from two previously identified families of malware, Gozi and Nymaim. Gozi was a widely distributed banking trojan with a known Domain Generation Algorithm (DGA) and also contained the ability to install a Master Boot Record (MBR) rootkit. Nymaim emerged in 2013 as malware which was used to deliver ransomware and was previously distributed by the Black Hole exploit kit. The code had various anti-analysis techniques, such as the obfuscation of Win32 API calls.
There have been multiple instances in which the source code of the Gozi trojan has been leaked. Due to these leaks it was possible for the GozNym authors to make use of the ‘best of breed’ methodologies incorporated into Gozi and create a significantly more robust piece of malware which was now capable of utilizing strengthened persistence methods and ultimately becoming a powerful banking trojan.
Given the recent success of the GozNym trojan and the number of targeted attacks seeking to infect victims with this malware, Talos decided to take a deep look at the inner workings of this particular malware family. Talos started by examining the binaries associated with GozNym as well as the distribution mechanisms. Additionally, we were able to successfully reverse engineer the DGA associated with a GozNym command and control (C2) infrastructure and sinkhole that botnet. This gave Talos great visibility into the size and scope of this threat and the number of infected systems beaconing to C2 servers under adversarial control.
This blog post was authored by Jaeson Schultz.
For the past five years we have enjoyed a relatively calm period with respect to spam volumes. Back at the turn of the decade the world was experiencing record-high volumes of spam. However, with the evolution of new anti-spam technologies, combined with some high-profile takedowns of spam-related botnets, voluminous and indiscriminate spam attacks fell precipitously in popularity with spammers. Subsequently, having lower volumes of spam to contend with, anti-spam systems had the luxury of dedicating more computer processing resources to analyzing fewer messages for email-based threats. But, as the fashion industry adage goes, “everything old is new again.” Spam volumes are back on the rise.
This post was authored by Jaeson Schultz.
Well it’s Microsoft Patch Tuesday, again, and that must mean we are girding our systems against another round of security vulnerabilities. This month Microsoft has released fourteen (14) bulletins covering fifty (50) security vulnerabilities. There are seven bulletins in the set whose severity is considered “Critical”. These “Critical” bulletins affect Internet Explorer, Microsoft Edge, Microsoft Graphics Component, Microsoft Exchange Server, Microsoft Office, OLE Automation for VBScript Scripting Engine, and the Adobe Flash Player. The remaining seven bulletins impact products such as Silverlight, Windows, Windows Kernel, Windows Lock Screen, Windows Secure Kernel Mode, Windows SMBv1 Server, and the Microsoft Windows PDF Library.
This blog authored by Nick Biasini.
Exploit kits are a class of threat that indiscriminately aims to compromise all users. Talos has continued to monitor this threat over time resulting in large scale research and even resulting in a large scale takedown. The focus of this investigation is on the tools and techniques being used to drive users to the exploit kits. This blog looks at the anatomy of a global malvertising campaign and how users interact with exploit kit gates, regardless of the sites they visit and the countries they reside.
Talos observed a large malvertising campaign affecting potentially millions of users visiting sites in North America, Europe, Asia Pac, and the Middle East. The research culminated in a joint effort with GoDaddy to mitigate the threat by taking back the registrant accounts used to host the activity, and taking down all applicable subdomains. This is yet another example of how organizations work together to stop threats affecting users around the globe. If you are a provider or online ad company that would like to work with Talos, please contact us.
Online advertising is a key component of the Internet today, especially for sites that provide content free of charge. In this blog we will be discussing a global malvertising campaign that has affected a wide array of websites. These websites don’t bear responsibility for these malicious ads; it is just the nature of online advertising. As security organizations get better at identifying and shutting down malicious content, adversaries are going to continue to move and stay agile. The advantage to malicious advertising is if you visit the same site twice you are unlikely to receive the same content from an advertising perspective. This is where protections like ad blockers, browsers with advanced sandboxing technologies, and detection/prevention technologies are paramount to ensure protection from this type of content.
Talos has discovered multiple vulnerabilities in Kaspersky’s Internet Security product which can be used by an attacker to cause a local denial of service attack or to leak memory from any machine running Kaspersky Internet Security software.
The vulnerabilities affect Kaspersky Internet Security 16.0.0, KLIF driver version 10.0.0.1532, but may affect other versions of the software too. Since anti-virus software runs with low level privileges on any system, vulnerabilities in these software are potentially very interesting for attackers. Although these vulnerabilities are not particularly severe, administrators should be aware that security systems can be used by threat actors as part of an attack, and keep such systems fully patched.
Vulnerabilities discovered by Piotr Bania and Marcin ‘Icewall’ Noga of Cisco Talos.
Vulnerability Spotlight: Multiple Remote Code Execution Vulnerabilities Within Lexmark Perceptive Document Filters.
Vulnerabilities discovered by Tyler Bohan & Marcin Noga of Cisco Talos.
Talos are today releasing three new vulnerabilities discovered within the Lexmark Perceptive Document Filters library. TALOS-2016-0172, TALOS-2016-0173 and TALOS-2016-0183 allow for a remote code execution using specifically crafted files.
These vulnerabilities are present in the Lexmark Document filter parsing engine which is used across a wide range of services such as eDiscovery, DLP, big data, content management and others. The library is commonly used across these services to allow for the deep inspection of a multitude of file formats to offer conversion capabilities such as from Microsoft document formats into other formats. Lexmark make this library available to compete against other third party and open source libraries used for such activities.
Document conversion represents an important aspect of many businesses as they attempt to move from an unstructured data solution to a more workable structured data solution in order to improve business efficiency.
The three vulnerabilities disclosed today allow for remote code execution using specifically crafted files such as XLS, Bzip2 & Compound Binary File Format (MS-CFB). This can provide an attacker with the capability to perform remote code execution within your environment and potentially offers the adversary full control of the attacked resource.