PC-cillin killed my PC

Update A duff anti-virus signature update on Friday from Trend Micro floored the PCs of many who applied it. The Japanese firm pulled the update 90 minutes after it was issued but the error caused mayhem to affected systems, particularly in Japan which because of the timing of the release was particularly badly hit.

The faulty update (pattern file 2.594.00) to Trend's OfficeScan, PC-cillin products as well as ServerProtect for NT and two of its small business packages, Client/Server Suite for SMB and Client/Server/Messaging Suite for SMB caused systems to freeze up. Reg reader Derek Law said his home PC stopped working after applying the OfficeScan and PC-cillin updates.

"Essentially, the update on Friday locked up all the CPU preventing anything from running," he said.

Another reader writes: "In the one and a half hours the update was up, it's likely to have been rolled out to every desktop in the enterprise."

Trend has apologised for this incident and pledged to improve its quality assurance procedures. Raimund Genes, head of EMEA operations at Trend Micro, said the pattern file was downloaded between 300,000 and 350,000 before Trend issued a corrected update. He said that because the release came out at 23:30 GMT on Friday night users in Japan were particularly badly hit. A reported 70,000 support calls were generated in Japan by the dodgy update. "There were not many enquiries in Europe," according to Genes. He added that Trend Micro has experienced glitches with signature updates before but has never one that had such a debilitating effect.

In a statement, Trend said that changes it made to its heuristic scanning functions to provide better detection for the prolific Rbot worm accidentally caused the reported system instability. The problem escaped detection prior to the release of the update because of an "isolated anomaly in the engineering, development and pattern release process". Users running the affected Trend products with either Win 2000 SP4 or Win 2003 SP1 on their servers or Win XP SP2 on the client were among those affected.

Trend reckons the update was not checked against XP SP2. Genes blamed human error for the glitch. He said the company was putting more resources in quality assurance as a short term measure. Longer term, Trend plans to update its Scan Engine to include a self-monitoring mechanism. Users are advised to upgrade to OPR 2.596.00 or higher.

Duff anti-virus signature updates are rare but not unprecedented and generally cause far less inconvenience than computer viruses. Nonetheless their very occurrence illustrates some of the pitfalls of the anti-virus scanner approach created by the need for frequent updates.

In this case its not just users who've been affected by the glitch. Trend Micro's share price fell 4.2 per cent to ¥4,100 on the news, Reuters reports. ®

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