Netsky worm another reminder of dangers of e-mail attachments

Two recent versions of the Netsky virus have infected computers across the world, causing extra work for Los Alamos' computer security staff.

Although irritating and potentially damaging for home computer users, Netsky actually may help Laboratory employees by reminding them to stay vigilant and never open attachments they aren't expecting.

One version, Netsky C, infected computers all over the Internet and bombarded Los Alamos' electronic mail system last week with messages originating outside the Laboratory. The other variant, Netsky B, hasn't gotten into the Lab e-mail system, but employees no doubt have encountered it when checking their personal e-mail elsewhere.

Netsky, in both forms, is a rapidly spreading mass-mailing worm that infects a computer, inserts copies of itself into e-mail attachments and sends them to addresses it finds on the computer. Current antivirus definitions will detect both versions of Netsky.

When Netsky infects a computer, it generates a wide variety of subject lines and message bodies, adds a copy of itself in an attachment, and sends the message and attachment to e-mail addresses it finds on the infected computer.

Some of the messages may look like they came from known senders inside or outside the Laboratory. The message may make it appear that you sent yourself a Netsky-infected message, even though you didn't. As always, computer users should not open e-mail attachments from unknown sources, and be cautious with attachments from known senders. Users should be particularly wary of unexpected attachments that end in .zip.

Filters on the Laboratory's e-mail system automatically remove the harmful attachments from incoming messages; however some of the messages, without attachments, get into Los Alamos mailboxes because of the large variety of Netsky-generated messages.

Messages that get through have a note and sometimes an attachment generated by the e-mail system reporting that a virus was found and deleted. Because some Netsky-generated messages also masquerade as virus notifications, the results can be confusing, even though Los Alamos computers are protected.

The Laboratory's e-mail system and automated antivirus updates are protecting the Labs' networks. Employees should make sure their personal computers are protected with up-to-date antivirus software.

For more information about Netsky.C, see Symantec's antivirus Web site at http://securityresponse.symantec.com/avcenter/venc/data/w32.netsky.c@mm.html online.

-- Jim Danneskiold

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