A faulty signature update from GRISoft published this week meant that its popular AVG anti-virus package falsely warned versions of Adobe Reader were infected with a Trojan.

Reg reader Tulio received a false alarm that his system was infected by SHueur-JXW after he downloaded Adobe Acrobat Reader 7.09. GRISoft acknowledged the problem and said that it planned it issue a new update that fixed the problem on Thursday. Faulty anti-virus signature updates are far from rare. Symantec, McAfee and others have all had problems in the area in recent months. False alerts are something of an Achilles heel for anti-virus scanning packages, a factor often highlighted by firms selling alternative approaches to malware detection (such as white listing). ®

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