A new variant of the infamous Waledac botnet client doing the rounds poses as a utility that allows would-be snoops to view other other people's SMS messages online.

The fake utility uses various filenames including sms.exe, freetrial.exe, and smstrap.exe but actually contain a variant of the Waledac malware. Anti-virus vendors are in the process of responding to the threat posed by spam emails containing the malware, which began circulating on Wednesday, but detection remains incomplete by Thursday afternoon.

"They are playing on people's nosey or suspicious nature, however the application doesn’t give the user the ability to spy on other people's SMS messages," said Carl Leonard, threat research manager at Websense. "Instead it installs a number of executable files to incorporate the user’s machine into Waledac's botnet. The irony is quite fitting, the user intended to spy on others but ends up being compromised themselves."

Security watchers are paying close attention to Waledac after the latest variant of the infamous Conficker superworm began downloading variants of the malware onto compromised machines late last week. ®

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