“I hate McAfee,” more than one Tweeter wrote, summing up the frustration felt when a McAfee update identified a “normal Windows process” as malware and killed it, kicking off a death spiral for the affected machines.

Another Tweet: “McAfee DAT 5958, you've made...no wait, what’s the opposite of "made my day"?... you've DESTROYED MY DAY. hate you McAfee. HAAATEEEEE.”

“VirusScan,” another person Tweeted. “The cure is worse than the disease.”

“Over 1000 PCs in my organization brought down by the very software that’s supposed to protect it,” wrote another.With McAfee’s Web site slammed by users looking for answers and getting none, users seemed incredulous that this flawed fix was released in the first place.

“Well,” said Robert Enger, a Los Angeles data communications and systems engineer, “McAfee to the rescue once again. :-( IT laptop croaked due to erroneous DAT file. I guess McAfee doesn't regression-test anything.”