Apple officials have instructed members of the company's support team to withhold any confirmation that a customer's Mac has been infected with malware or to assist in removing malicious programs, ZDNet's Ed Bott reported on Thursday.

He cited an internal document titled "About 'Mac Defender' Malware," which was last updated on May 16 and says that the trojan, which surfaced earlier this month and masquerades as legitimate security software for the OS X platform, is an "Issue/Investigation In Progress."

"AppleCare does not provide support for removal of the malware," the document, which was labeled confidential, stated. "You should not confirm or deny whether the customer's Mac is infected or not."

The memo's disclosure comes as the number of reported Mac attacks has skyrocketed, Bott said. According to an earlier article he published, he recently found more than 200 separate discussion threads on discussions.apple.com in which users complained of infections that caused their Macs to behave erratically.

"Porn sites just started popping up on my MacBook Pro," one user wrote. "Is this a virus? I have never had a virus on a Mac before and I have been using Macs for years. Please help!"

The con artists behind Mac Defender hook their victims by presenting Mac-using web surfers with images that depict an antivirus scan taking place on their machines. The images falsely claim users are infected with serious malware and urge them to download and install the antivirus package. Those who fall for the ruse are then infected. Similar scams have plagued Windows users for years, often to the delight and scorn of Mac and Linux fans.

According to a third article penned by Bott, AppleCare reps are seeing a four- to five-fold increase in the number of calls requesting support for rogue antivirus scams targeting the Mac. ®