The method -- downloading key generators that unlock trial software so it can be used beyond the trial period -- is fraught with peril to the users' computer safety yet is used so often that it now represents the most common threat recorded by the latest report, says Tim Rains, director of product management for Microsoft's Trustworthy Computing group.
In 2010 Rains says he noted that key generators were found on a growing number of the machines worldwide from which Microsoft gleans data for its reports. In the first half of this year, that number had grown by a factor of 26 to 5 million and spread from mainly the U.S., Russia, Brazil, China and Spain to 103 of the 105 countries monitored.
Of those machines found with key generation software, 76% were also found to have some other form of malware. Rains makes a link between the two, saying that the sites from which the key-gen software is downloaded may dump malware on machines that visit. But also, the key generators themselves may contain malware that executes when the generator is used or it might turn out the purported generators are actually Trojans, he says.
Discovery of key-gen software has been rising in enterprises, from 7.6% of machines in the third quarter of last year to 10.2% in the second quarter this year, Rains says. Key generators are the No. 1 detected threat on all Windows 7 machines and the No. 6 threat on Windows XP machines with Service Pack 3, he says.
Software for which victims commonly download key generators includes AutoCAD, Nero Multimedia, Adobe Photoshop and Call of Duty.
Rains says Microsoft doesn't try to determine which key-gen software is legitimate and which is not, but those that are illegitimate attract users who think they can extend trial periods for software they've been trying out.
Some of the malware is named to appear as if it is the key generator the users seek. For example, one piece of malware is called installadobeflash.exe, he says. "They're trying to fool people into thinking they're getting trial or legitimate software," he says, "when they can get it for free at no risk from Adobe."
Other malware code bears names that indicate it is for Firefox, Google Earth and Microsoft Security Essentials, Rains says. Some of the malware is disguised to look like video or music downloads, including songs by Lady Gaga, Pitbull and Maroon 5, as well as videos of "The Avengers," "Prometheus" and "The Hunger Games."
The malware can do a range of things from extracting personally identifiable information used to steal identities to stealing passwords for email and banking, he says.
To avoid falling victim, Rains recommends downloading only from trusted sites. "If you don't trust the site, don't trust the software," he says. Users should also follow standard safe practices such as keeping operating systems patched, updating antivirus software regularly, employing browser security, enabling firewalls, using strong passwords and never browsing when logged in as an administrator.