Malicious Microsoft Security Update spammed out before Patch Tuesday

Graham Cluley
@gcluley

Hackers are trying to infect innocent computer users with a malicious Trojan horse disguised as a Microsoft security update, in the hours before the software giant issues genuine critical patches as part of its monthly “Patch Tuesday” cycle.

The emails, which have the subject line “Security Update for OS Microsoft Windows” and claim to come from Steve Lipner at [email protected], try to fool unsuspecting computer users that the attached file is a high priority update that should be installed by users of various flavours of Microsoft Windows.

However, running the attached file infects Windows computer users with the Mal/EncPk-CZ Trojan horse, and could give hackers control over your PC. The file attached to the file is named KBxxxxxx.exe (where ‘xxxxxx’ is a randomly generated number) in order to disguise itself as a knowledgebase file.

Computer users need to learn that…

Read more in my article on the Naked Security website.

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Graham Cluley is a veteran of the anti-virus industry having worked for a number of security companies since the early 1990s when he wrote the first ever version of Dr Solomon's Anti-Virus Toolkit for Windows. Now an independent security analyst, he regularly makes media appearances and is an international public speaker on the topic of computer security, hackers, and online privacy. Follow him on Twitter at @gcluley, on Mastodon at @[email protected], or drop him an email.