AVG's free antivirus product temporarily blocked users from getting to iTunes late last week, detecting it as a Trojan, the company said on Monday.
For about five hours on Friday starting around 4 p.m. PDT, AVG users couldn't access iTunes because of the false alarm.
"AVG discovered the false alarm in the virus signature engine relating to some localization components of iTunes (so not iTunes as a virus but rather some localization components of iTunes) and it was fixed within 5 hours," AVG spokesperson Siobhan MacDermott said in a statement. "AVG would like to apologize for any inconvenience to our users/customers."
AVG was alerted to the problem by customers, who were posting to the AVG and iTunes forums.
While irregular, false positives do happen. Last year, AVG flagged ZoneAlarm as malware and a Windows system file as a Trojan. And earlier this month, Computer Associates' antivirus software mistakenly identified a Windows XP systems file as a virus.