MSRT February 2017: Chuckenit detection completes MSRT solution for one malware suite

In September 2016, we started adding to Microsoft Malicious Software Removal Tool (MSRT) a malware suite of browser modifiers and other Trojans installed by software bundlers. We documented how the malware in this group install other malware or applications silently, without your consent. This behavior ticks boxes in the evaluation criteria that Microsoft Malware Protection…

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Windows 10: protection, detection, and response against recent Depriz malware attacks

A few weeks ago, multiple organizations in the Middle East fell victim to targeted and destructive attacks that wiped data from computers, and in many cases rendering them unstable and unbootable. Destructive attacks like these have been observed repeatedly over the years and the Windows Defender and Windows Defender Advanced Threat Protection Threat Intelligence teams…

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Fake fax ushers in revival of a ransomware family

“Criminal case against you” is a message that may understandably cause panic. That’s what a recent spam campaign hopes happens, increasing the likelihood of recipients opening the malicious attachment. We recently discovered a new threat that uses email messages pretending to be fax messages, but in truth deliver a ransomware downloader. The attachment used in this…

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The new .LNK between spam and Locky infection

Just when it seems the Ransom:Win32/Locky activity has slowed down, our continuous monitoring of the ransomware family reveals a new workaround that the authors might be using to keep it going. The decline in Locky activity can be attributed to the slowdown of detections of Nemucod, which Locky uses to infect computers. Nemucod is a…

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MSRT October 2016 release: Adding more unwanted software detections

Unwanted software often piggy-backs on program downloads, delivered by software bundlers. These bundles, which you might have downloaded, can include software that you do not want, and some that are harmful. The bundled or “extra” software can perform actions on your device that run the gambit from unwanted to annoying to malicious. The threat that…

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Nemucod dot dot..WSF

The latest Nemucod campaign shows the malware distributing a spam email attachment with a .wsf extension, specifically ..wsf (with a double dot) extension. It is a variation of what has been observed since last year (2015) – the TrojanDownloader:JS/Nemucod malware downloader using JScript. It still spreads through spam email attachment, typically inside a .zip file,…

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Kovter becomes almost file-less, creates a new file type, and gets some new certificates

Trojan:Win32/Kovter is a well-known click-fraud malware which is challenging to detect and remove because of its file-less persistence on infected PCs. In this blog, we will share some technical details about the latest changes we have seen in Kovter’s persistence method and some updates on their latest malvertising campaigns. New persistence method Since June 2016,…

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Large Kovter digitally-signed malvertising campaign and MSRT cleanup release

Kovter is a malware family that is well known for being tricky to detect and remove because of its file-less design after infection. Users from United States are nearly exclusively being targeted, and infected PCs are used to perform click-fraud and install additional malware on your machine. Starting April 21, 2016, we observed a large…

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