Mydoom.O hammering search engines

IDG News Service - Antivirus software companies are warning e-mail users about a new version of the Mydoom e-mail worm, dubbed Mydoom.O, which is spreading on the Internet and causing slowdowns at search engines, including those run by Lycos Inc. and Google Inc.
Leading antivirus software companies issued alerts for Mydoom.O, which was first detected today and arrives in e-mail message attachments that, when opened, install the virus and create a back door that remote attackers can use to access infected machines. While similar to other versions of Mydoom, the "O" variant is testing a new approach: using major search engines to harvest e-mail addresses on Web domains that it discovers, thus slowing those sites, according to Johannes Ullrich, chief technology officer at the SANS Institute's Internet Storm Center.
"The standard scheme is for viruses to look [for e-mail addresses] in the Web cache," he said, referring to the previously visited Web pages stored on computer hard drives. But if Mydoom.O finds an e-mail address, in addition to sending a copy of itself to the address, it also does a search on the Web domain and uses the results to discover more addresses in that domain, according to Ullrich.
Ullrich estimated that "a couple hundred thousand machines" may be infected with MyDoom.O. Those machines can generate huge volumes of search requests, which appear to be bogging down major search engines.
The worm targets Google, Yahoo and Lycos. The AltaVista search engine owned by Overture Services Inc. is also a target, according to a statement from Computer Associates International Inc.
A spokesman for Google acknowledged that visitors experienced slowness for a short period of time that the company believes was related to the Mydoom worm. The spokesman could not say whether some users were still experiencing slow response at Google.com but noted that the Google Web site was not "significantly impaired" by the attacks. Technical staff members at the company are investigating the slowdowns and expect to have service restored for all users shortly, he said.

Yahoo said it noticed the effect of the virus on Yahoo's search engine as result of ongoing surveillance early today and implemented "backup procedures" to compensate for the increased traffic. There was "minimal latency" on its site this morning but that traffic and systems were running "normally" later in the day, according to Stephanie Ichinose, a Yahoo spokeswoman.
McAfee Inc. rated the new Mydoom version a "medium" threat, citing a large number of virus samples received by the company. Symantec Corp. ranked the worm, which it dubbed Mydoom.M, a