Microsoft Malware Protection Center

Threat Research & Response Blog

Microsoft Malware Protection Center

  • Sefnit’s Tor botnet C&C details

    ​We have talked about the impact that resulted from the Sefnit botnet Tor hazard as well as the clean-up effort that went into that threat. In this post we’d like to introduce some of the details regarding the Tor component’s configuration and its communication with the Tor service. Specifically, we’ll talk about how Trojan:Win32/Sefnit.AT communicates with the Tor network, what domains it tries to contact, and where it keeps its configuration data. After Sefnit installs the...
  • A close look at a targeted attack delivery

    For antimalware products, targeted attacks represent a very interesting class of malware. They are stealthy and only target specific organizations and industries - flying under the radar when it comes to identifying new malware files based on telemetry. The purpose of these attacks is most commonly to steal confidential and sensitive information by means of social engineering and unpatched, vulnerable software. We recently investigated a sample used in this kind of attack, Trojan:Win32/Retefe...
  • MSRT April 2014 – Ramdo

    This month we added Win32/Ramdo and Win32/Kilim to the Microsoft Malicious Software Removal Tool. In this blog, we will focus on Ramdo and some of what we have since found out about this relatively new trojan family. Ramdo, a click-fraud bot with built-in antisinkhole and antivirtualization code, was first found in the wild in December 2013. Telemetry Compared to other big families, Win32/Ramdo’s impact is relatively small in terms of the number of infected machines. However, when one...
  • Febipos for Internet Explorer

    In a previous blog post we discussed Trojan:JS/Febipos.A , a malicious browser extension that targets the Facebook profiles of Google Chrome and Mozilla Firefox users. We recently came across a new Febipos sample that was specifically developed for Internet Explorer - we detect it as Trojan:Win32/Febipos.B!dll . This trojan is a browser helper object that loads a JavaScript to Internet Explorer. We detect the loaded JavaScript as Trojan:JS/Febipos.E . The plugin tries to look legitimate by calling...
  • The MSRT in Action: Keeping systems safe

    In four days the January release of the Microsoft Malicious Software Removal Tool (MSRT) detected almost a million threats on PCs across the globe. In the video below, Dustin Childs and Joe Faulhaber explain what happened as the MSRT sprang into action.
  • MSRT September 2014 - Zemot

    ​This month we added the Win32/Zemot family to the Malicious Software Removal Tool . The Zemot family of trojan downloaders are frequently used by malware with a number of different payloads. We started seeing activity from TrojanDownloader:Win32/Upatre.B in late 2013 and identified this threat as the main distributor of the click fraud malware PWS:Win32/Zbot.gen!AP and PWS:Win32/Zbot.CF . We renamed the downloader to Zemot in May 2014. Recently, other malware such as Win32/Rovnix , Win32/Viknok...
  • Backup the best defense against (Cri)locked files

    Crilock – also known as CryptoLocker – is one notorious ransomware that’s been making the rounds since early September. Its primary payload is to target and encrypt your files, such as your pictures and Office documents. All of the file types that can be encrypted are listed in our Trojan:Win32/Crilock.A and Trojan:Win32/Crilock.B descriptions. Crilock affected about 34,000 machines between September and early November 2013. Once Crilock encrypts your file types, they are...
  • Creating an intelligent “sandbox” for coordinated malware eradication

    ​Hello from China where I am presenting on coordinated malware eradication at the 2014 PC Security Labs Information Security Conference . Coordinated malware eradication was also the topic of my last blog . I said the antimalware ecosystem must begin to work with new types of partners if we are going to move from the current state of uncoordinated malware disruption , to a state of coordinated malware eradication . Since then we’ve been talking about these ideas at conferences around the...
  • Turkey: Understanding high malware encounter rates in SIRv15

    In our most recent version of the Security Intelligence Report (SIRv15) , we compared the encounter rates of malware categories for the top 10 countries with computers reporting the most detections in 2Q13. Amongst these countries, Turkey stood out with considerably high encounter rates in multiple categories. Encounter rate is the percentage of computers in a country that reported at least one detection of malware. Figure 1. Threat category prevalence worldwide and in the 10 locations with...
  • A journey to CVE-2014-0497 exploit

    ​Last week we published a blog post about a CVE-2013-5330 exploit . We’ve also recently seen a new, similar attack targeting a patched Adobe Flash Player vulnerability ( CVE-2014-0497 ). The vulnerability related to this malware was addressed with a patch released by Adobe on February 4, 2014 . Flash Player versions 12.0.0.43 and earlier are vulnerable. We analyzed how these attacks work and found the following details. The malicious file has been distributed as a .swf file, which contains...