Known as Winevar, the computer worm arrives in e-mail as an attachment that infects Windows PCs when opened and displays a dialog box pronouncing, "What a foolish thing you have done!"
Despite the playful tone however, the virus is no joke.
"Winevar has several extremely dangerous payloads, which can lead to the irrecoverable loss of data," Russian antivirus firm Kaspersky Labs said in an advisory released Wednesday.
According to Kaspersky, the virus was discovered last week, but has only started to spread in earnest recently.
The virus spreads using e-mail by attaching itself to a message as a .pif or .ceo attachment. The message will appear to be from fictional organizations N'4 or the Association of Anti-Virus Asia Researchers (AVAR).
Once opened, the worm attempts to halt several antivirus programs and other security software from running on the PC. In some cases, Winevar also attempts to delete every file on the computer, antivirus firm Symantec stated in its advisory.
Symantec and other antivirus software firms recommend that computer users don't open attachments, especially those ending in .pif and .ceo, and update their virus definitions.