Microsoft Malware Protection Center

Threat Research & Response Blog

Microsoft Malware Protection Center

  • Microsoft antimalware support for Windows XP

    Microsoft has announced the Windows XP end of support date of April 8, 2014. After this date, Windows XP will no longer be a supported operating system * . To help organizations complete their migrations, Microsoft will continue to provide updates to our antimalware signatures and engine for Windows XP users through July 14, 2015. This does not affect the end-of-support date of Windows XP, or the supportability of Windows XP for other Microsoft products, which deliver and apply those signatures...
  • Adware: A new approach

    ​Here at the Microsoft Malware Protection Center (MMPC) we understand advertising is part of the modern computing experience. However, we want to give our customers choice and control regarding what happens with their computers. To that end we have recently undergone some changes to both the criteria we use to classify a program as adware and how we remediate it when we find it. This blog will help explain the new criteria and how it affects some programs. Our updated objective criteria also explains...
  • The fall of rogue antivirus software brings new methods to light

    Rogue antivirus software has been a part of the malware ecosystem for many years now – Win32/SpySheriff and Win32/FakeRean date all the way back to 2007. These rogues, and the many that have followed them throughout the years, generally mislead and scare users into paying a fee for "cleaning" false detections that the software claims to have found on the machine. They often use dozens of different brandings and name combinations in an attempt to hide, cover their tracks, and avoid...
  • Tackling the Sefnit botnet Tor hazard

    Sefnit, a prevailing malware known for using infected computers for click fraud and bitcoin mining, has left millions of machines potentially vulnerable to future attacks. We recently blogged about Sefnit performing click fraud and how we added detection on the upstream Sefnit installer . In this blog we explain how the Tor client service, added by Sefnit, is posing a risk to millions of machines, and how we are working to address the problem. Win32/Sefnit made headlines last August as it took...
  • Infection rates and end of support for Windows XP

    In the newly released Volume 15 of the Microsoft Security Intelligence Report (SIRv15), one of the key findings to surface relates to new insight on the Windows XP operating system as it inches toward end of support on April 8, 2014. In this post we want to highlight our Windows XP analysis and examine what the data says about the risks of being on unsupported software. In the SIR, we traditionally report on supported operating systems only. For this analysis we examined data from unsupported...
  • Microsoft Digital Crimes Unit disrupts Jenxcus and Bladabindi malware families

    ​Today, following an investigation to which the Microsoft Malware Protection Center (MMPC) contributed, the Microsoft Digital Crimes Unit initiated a disruption of the Jenxcus and Bladabindi malware families. These families are believed to have been created by individuals Naser Al Mutairi, aka njQ8, and Mohamed Benabdellah, aka Houdini. These actions are the first steps to stop the people that created, distributed, and assisted the propagation of these malware families. There are more details...
  • Malicious Proxy Auto-Config redirection

    Internet banking credentials are a desired target for cybercriminals. They can be targeted with man-in-the-middle attacks or through password stealing trojans such as Fareit , Zbot or Banker . A less known, yet commonly found in South America and to a lesser extent in Russia, method to gain unauthorized access to a user’s banking credentials is through malicious Proxy Auto-Config (PAC) files. Normally, PAC files offer similar functionality to the hosts file, allowing IP/website redirection...
  • 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...
  • 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...
  • Coordinated malware eradication

    Today, as an industry, we are very effective at disrupting malware families, but those disruptions rarely eradicate them. Instead, the malware families linger on, rearing up again and again to wreak havoc on our customers. To change the game, we need to change the way we work. It is counterproductive when you think about it. The antimalware ecosystem encompasses many strong groups: security vendors, service providers, CERTs, anti-fraud departments, and law enforcement. Each group uses their...