ICQ members are identified by numbers. With more than 42 million registrations, newer numbers have become quite lengthy, making the shorter numerical IDs of early ICQ adopters hot properties.
Now those shorter name tags are the targets of theft, as malicious hackers are distributing a Trojan horse that steals passwords and commandeers control of ICQ accounts.
A Trojan horse is a piece of computer code that behaves in an unexpected, usually nefarious manner. In this case, the Trojan is disguised as a JPEG image file, distributed by email, that steals the ICQ password from the user's hard drive.
AOL, which bought ICQ last year, said it had anticipated the theft of low-numbered ICQ accounts and had provided a way of verifying the authenticity of the accounts' original owners and restoring control to them. Users whose passwords have been stolen can be re-authenticated at ICQ.com.
So far, about 200 ICQ users have reported having their passwords stolen in recent weeks, AOL said.
The Trojan was first reported by Wired News.