CCleaner malware incident

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A recent version of the popular Windows cleanup tool CCleaner contains malware, apparently added by malicious persons who gained access to a server used by the software developer, Piriform.

The malware was found only in the 32-bit version of CCleaner 5.33.6162. No other versions were affected.

Piriform reacted quickly to the discovery, and yesterday released a new version: CCleaner 5.34.

If you have CCleaner installed on any Windows computers, you should make sure you’re running version 5.34, and if not, install it as soon as possible.

Update 2017Sep23: The server that was breached is actually managed by Avast, which purchased CCleaner software developer Piriform in July.

Ongoing analysis of the hack revealed that this may have been a state-sponsored attack, and that it specifically targeted high profile technology companies. Apparently the malware in the compromised version of CCleaner contained a second payload that was only installed on about twenty computers at eight tech companies.

About jrivett

Jeff Rivett has worked with and written about computers since the early 1980s. His first computer was an Apple II+, built by his father and heavily customized. Jeff's writing appeared in Computist Magazine in the 1980s, and he created and sold a game utility (Ultimaker 2, reviewed in the December 1983 Washington Apple Pi Journal) to international markets during the same period. Proceeds from writing, software sales, and contract programming gigs paid his way through university, earning him a Bachelor of Science (Computer Science) degree at UWO. Jeff went on to work as a programmer, sysadmin, and manager in various industries. There's more on the About page, and on the Jeff Rivett Consulting site.

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