McAfee customers had internet access severed and were left exposed to malware after the company issued a glitched anti-virus update.
The update affected all Windows McAfee suites and VirusScan products including the latest version of VirusScan Enterprise and McAfee Security Center.
Anti-virus signature updates (DAT 6807, 6808) would disable the anti-virus clients, and in some cases sever internet access.
McAfee overnight issued an enterprise 100Mb Super DAT (Hotfix 793640) and a consumer fix (DAT 6809) for the borked updates which it rated as ‘critical’.
Enterprise customers had to apply the hotfix as a product update through the e-policy orchestrator, while consumers were advised to remove McAfee from affected machines and re-install the product in order for the fix to be applied.
Furious enterprise and business customers posted comments yesterday on the McAfee blog claiming they were left high and dry after thousands of machines within their companies were left exposed by the updates.
“I currently have over 3000 endpoints with this problem - solution ASAP please McAfee,” customer Derosa wrote.
Another customer, Bostjanc, said they had 46 of 152 machines affected. “Soo theoretically if one of those users … gets a virus and spreads out to rest of the 45 computers, what then?"
“Then I'm f***ed as an anti-virus technical support.”
Another user had 70 systems of 2100 affected, including two "high profile" users.
Meanwhile, some consumers took to McAfee’s Facebook account to vent anger where support officers were assisting with technical support.
The borked update followed one issued by McAfee in April that crashed email services, and another by Microsoft for its anti-virus product that flagged Google as hosting the malicious Blackhole exploit kit.
AusCERT security analyst Jonathan Levine said organisations should test antivirus updates before live deployment.
“Everything should be tested before going live as part of best practice,” Levine said.
But he doubted many organisations would bother with testing.
Some users writing on the SANS Internet Storm Center supported the suggestion, saying the cost of testing may outweigh the resources to fix “the occasional glitch”.
Others had comprehensive testing procedures. One McAfee user ran an 18-hour delayed deployment schedule in their organisation in which an evaluation branch would test DAT files on a group of servers and workstations before releasing it to another branch for staggered deployment the next day.
“This has saved us during the bad DAT times … if there is an issue, we are usually only one or two DAT releases behind but catch up during the day,” they said.