Home page logo

isn logo Information Security News mailing list archives

Nimda resurgence falls flat
From: InfoSec News <isn () c4i org>
Date: Mon, 1 Oct 2001 05:18:28 -0500 (CDT)


By Robert Lemos
Special to CNET News.com 
September 28, 2001, 4:00 p.m. PT 

A resurgence of the Nimda worm failed to materialize Friday, leaving
unfulfilled warnings that several security companies made this week.

The e-mail component of the worm, which sends infected messages to
each entry in an infected computer's Outlook address book, reactivates
10 days after the original infection. That part of the program had
antivirus researchers and security experts worried that the Nimda worm
was again set to spread quickly.

But Friday morning, 10 days after the first infections started to take
hold, few signs heralded a return of the worm.

"We have been checking throughout the entire day, and we are not
seeing anything," said John Harrington, director of marketing for
e-mail filtering service MessageLabs. "Our gut feeling is that it is
not going to happen."

According to MessageLabs' Web site, the company has detected fewer
than 1,600 copies of the virus since the start of the epidemic 10 days

Nimda--which is "admin," the shortened form of "system administrator,"
spelled backward--started spreading Sept. 18 and quickly infected PCs
and servers around the world. Also known as "readme.exe" and
"W32.Nimda," the worm is the first to use four different methods to
infect not only PCs running Windows 95, 98, Me and 2000, but also
servers running Windows 2000.

The worm spreads by e-mailing itself as an attachment, scanning for
and then infecting vulnerable Web servers running Microsoft's Internet
Information Server software, copying itself to shared disk drives on
networked PCs, and appending JavaScript code to Web pages that will
download the worm to surfers' PCs when they view the page.

The e-mail component of the worm sends Nimda-infected messages every
10 days, counting from when the victim was originally infected. Since
the virus is thought to have started Sept. 18 at 8:30 a.m. PDT, the
first new e-mails should have started going out early Friday.

Only a few infected computers may be left, however.

Anti-virus software maker Trend Micro said that while some companies
reported infections Friday, the number is still low.

"We've seen a few infections in organizations that haven't done a
complete cleaning, but it's limited," said company spokeswoman Susan

Furthermore, compromised servers and PCs without Outlook installed
will only have a limited number of e-mail addresses to which to send
messages. The worm also scans the browser cache on computers for saved
Web pages that contain e-mail addresses and sends infected messages to
those addresses as well.

Servers that aren't used to browse the Internet will not have such a

ISN is currently hosted by Attrition.org

To unsubscribe email majordomo () attrition org with 'unsubscribe isn' in the BODY
of the mail.

  By Date           By Thread  

Current thread:
  • Nimda resurgence falls flat InfoSec News (Oct 01)
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]