Popular free of charge anti-virus scanner Avast went berserk late last week and began classifying legitimate files as infected.

Legitimate products were wrongly classified as harbouring the Dell-MZG Trojan or other strains of malware and whisked off to quarantine following the publication of a dodgy update. Avast has published a new update that eliminates the wrongful classification glitch. However, that still leaves users who applied the earlier update with borked systems.

False positives are a well known shortcoming of anti-malware scanners. Avast's snafu last Thursday was only unusual because it classified a large number of legitimate programmes as malign. Software from Adobe, Realtek sound card drivers and various media players were all affected.

Avast has published an apology for the cock-up and advice on restoring systems in a blog post (here) and its forum (here).

The anti-virus firm blamed "human error" for the mix-up. ®

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