W32.Mydoom.A@mm

Due to a decreased rate of submissions, Symantec Security Response has downgraded this threat from a Category 3 to a Category 2 rating as of March 30, 2004.

W32.Mydoom.A@mm (also known as W32.Novarg.A) is a mass-mailing worm that arrives as an attachment with the file extension .bat, .cmd, .exe, .pif, .scr, or .zip.

When a computer is infected, the worm sets up a backdoor into the system by opening TCP ports 3127 through 3198, which can potentially allow an attacker to connect to the computer and use it as a proxy to gain access to its network resources.

In addition, the backdoor can download and execute arbitrary files.

There is a 25% chance that a computer infected by the worm will perform a Denial of Service (DoS) on February 1, 2004 starting at 16:09:18 UTC, which is also the same as 08:09:18 PST, based on the machine's local system date/time. If the worm does start the DoS attack, it will not mass mail itself. It also has a trigger date to stop spreading/DoS-attacking on February 12, 2004. While the worm will stop on February 12, 2004, the backdoor component will continue to function after this date.

---

Notes:

• Symantec Consumer products that support Worm Blocking functionality automatically detect this threat as it attempts to spread.
• Virus definitions dated prior to February 4, 2004 will detect this threat as W32.Novarg.A@mm.

---

When W32.Mydoom.A@mm sends email, it avoids distributing to the domains that contain any of the following strings:

• avp
• syma
• icrosof
• msn.
• hotmail
• panda
• sopho
• borlan
• inpris
• example
• mydomai
• nodomai
• ruslis
• .gov
• gov.
• .mil
• foo.
• berkeley
• unix
• math
• bsd
• mit.e
• gnu
• fsf.
• ibm.com
• google
• kernel
• linux
• fido
• usenet
• iana
• ietf
• rfc-ed
• sendmail
• arin.
• ripe.
• isi.e
• isc.o
• secur
• acketst
• pgp
• tanford.e
• utgers.ed
• mozilla
  
  
  accounts that match any of the following strings:

• root
• info
• samples
• postmaster
• webmaster
• noone
• nobody
• nothing
• anyone
• someone
• your
• you
• me
• bugs
• rating
• site
• contact
• soft
• no
• somebody
• privacy
• service
• help
• not
• submit
• feste
• ca
• gold-certs
• the.bat
• page
  
  
  or accounts that contain any of the following strings:

• admin
• icrosoft
• support
• ntivi
• unix
• bsd
• linux
• listserv
• certific
• google
• accoun

The worm also prepends any of the following names to the domain name obtained:

• adam
• alex
• alice
• andrew
• anna
• bill
• bob
• brenda
• brent
• brian
• claudia
• dan
• dave
• david
• debby
• fred
• george
• helen
• jack
• james
• jane
• jerry
• jim
• jimmy
• joe
• john
• jose
• julie
• kevin
• leo
• linda
• maria
• mary
• matt
• michael
• mike
• peter
• ray
• robert
• sam
• sandra
• serg
• smith
• stan
• steve
• ted
• tom