A computer virus that gives hackers access to information such as passwords and credit-card numbers held on personal computers is spreading on the Internet.
Dubbed BugBear.B, it follows two other similar viruses but far exceeds them in its ability to do harm.
US e-mail filtering company MessageLabs Inc has already blocked 37,400 copies of the bug from 125 countries; the virus was almost non-existent on Wednesday.
Network Associates says it had received 100 infection reports from corporate and consumer customers as of this morning.
Once an e-mail with the virus is opened it will spread throughout an entire network.
Infected e-mails can carry various "from" addresses, which do not necessarily belong to the real sender. The subject lines and message texts also vary widely and in some cases are stolen from documents and files found on the victim's PC. The virus-laden attachment is compressed with a modified UPX format and shows up with multiple names.
BugBear.B, which is a variant of the BugBear virus that struck in late September 2002, installs a hidden file that can allow hackers to access infected machines, where they could delete files or run programs of their choosing.
Because the virus installs a keylogger program that collects a user's keystrokes, including passwords and credit-card numbers entered into websites, hackers could use their access to the PC to acquire such sensitive personal information.
AP