Microsoft Malware Protection Center

Threat Research & Response Blog

Microsoft Malware Protection Center

  • 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...
  • 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...
  • Be a real security pro - Keep your private keys private

    One of the many unusual characteristics of the Stuxnet malware that was discovered in 2010 was that its files were distributed with a valid digital signature, created using authentication credentials that belonged to two unrelated legitimate software companies. Normally the signature would verify that the program was issued by the company listed in the signing certificate, and that the contents of the program had not been tampered with since it was signed. By using other companies’ authentication...
  • 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...
  • Coordinated malware eradication nears launch

    ​Good news: the coordinated malware eradication preparations are almost done. We have held several roundtable meetings at industry events around the world, and the last two are scheduled for June and July. We had insightful conversations with a diverse group of experts from across the antimalware industry. The ideas have converged into a shared vision of how we’ll work together to put pressure on the malware ecosystem. I am excited for the first coordinated eradication campaigns to launch!...
  • FireEye and Fox-IT tool can help recover Crilock-encrypted files

    Since file-encryption ransomware Crilock (also called CryptoLocker) has reared its head, the security industry has been hard at work finding ways to mitigate and neutralize these threats. We've also been hard at work finding ways to recover from the encryption and restore affected files - such as our recommendations on using version control and recovery options in SkyDrive and Windows . This week, researchers from FireEye and Fox-IT have released a tool that may be able to recover files encrypted...
  • USB firmware: An upcoming threat for home and enterprise users

    Every year, thousands of hackers and security researchers from around the world descend on Las Vegas to attend the annual Black Hat security conference. The conference boasts top notch security presentations from industry leaders – often centered on breaking computer security. Although many of the presentations are on breaking things, most of the attendees and presenters are in fact using the knowledge for good – to design more secure software, better secure their organization, or fix...
  • Mevade and Sefnit: Stealthy click fraud

    ​Recently Trojan:Win32/Mevade made news for being the first large botnet to use Tor to anonymize and hide its network traffic. Within a few weeks, starting mid-August, the number of directly connecting Tor users increased by almost 600 percent - from about 500,000 users per day to more than 3,000,000. Last week we concluded, after further review, that Mevade and Sefnit are the same family and our detections for Mevade have now been moved to join the Sefnit family. Win32/Sefnit is a well-known...
  • 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...
  • SIRv16: Cybercriminal tactics trend toward deceptive measures

    Microsoft’s Security Intelligence Report volume 16 (SIRv16) was released today, providing threat trends on malware encounter rates, infection rates, vulnerabilities, exploits, and more for 110 countries/regions worldwide. The report is designed to help IT and security professionals better protect themselves and their organizations from cyberattacks. Malware data is gathered from the Malicious Software Removal Tool (MSRT), which is used to calculate the infection rate ( Computers Cleaned...