F-Secure Virus Descriptions : MyDoom.AC
[Summary] | [Detailed Description] | [Detection]
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A new variant of MyDoom worm - Mydoom.AC, was found in the middle
of September 2004. This worm variant can spread in e-mails as a
fake FlashEcard virtual postcard.
The worm is a PE executable file 23040 bytes long packed with
PECompact and PECBundle file compressors and modified by
PE_Patch. The unpacked file's size is over 61 kilobytes.
Installation to system
When run, the worm starts Internet Explorer and goes to
'www.microsucks.com' website as a disguise.
Then the worm creates a mutex 'holla_back_bitches', copies itself
as SYSHOSTS.EXE to Windows System Directory and creates a startup
key for that file in System Registry:
[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"MS Updates" = "%WinSysDir%\syshosts.exe"
where "%WinSysDir%" represents Windows System directory.
Spreading in e-mails
The worm spreads by sending its infected attachment to all e-mail
addresses found on an infected computer. The worm looks for
e-mail addresses in Windows Address Book and in the files with
the following extensions:
txt
htm
html
sht
php
eml
msg
asp
dbx
tbb
adb
pl
wab
The worm avoids sending e-mails to e-mail addresses that contain
any of the following substrings:
icrosof
syma
msn
hotmail
anda
opho
borlan
npris
xample
mydom
@domai
ruslis
.gov
.gov
.mil
@foo
berkeley
unix
math
bsd
mit.e
gnu
fsf.
ibm
oogle
kernel
linux
fido
senet
@ian
ripe
isi.e
arin.
rfc-ed
isc.o
ecur
acketst
pgp
tanford.e
utgers.ed
ample
info
root@
ostmaster@
ebmaster@
you
ugs@
ating@
ontact@
soft
rivacy
ervice
help
ubmit@
feste
cert
page
upport
ntivi
istser
ertific
ccoun
spm
Spam
SPAM
spam
abuse
cafee
@messagelab
@avp
kasp
winzip
winrar
pdate
irus
ahoo
buse@
sale
The subject of infected e-mails is selected from the following
variants:
album
You've got a Virtual Postcard!
The body text of infected e-mails is selected from the following
variants:
my pics...*sexy*. Heheh! ;)
or
You have just received a new postcard from Flashecard.com!
From:
To pick up your postcard follow this web address
http://www.flashecard.com.viewcard.main.ecard.php?2342
or click the attached link.
We hope you enjoy your postcard, and if you do, please
take a moment to send a few yourself!
(Your message will be available for 30 days.)
Please visit our site for more information.
http://www.flashecard.com
The worm can send itself as an executable attachment or in a ZIP
archive with one of the following names:
photos_album
www.flashecard.com?postcard=viewcard?download
The extension of an infected file can be any of the following:
.scr
.html.scr
The worm fakes the sender's address. It uses the following list
of names to compose the fake address:
Jennifer
Barbara
Linda
Susan
Eric
Kevin
Mary
Robert
John
Maria
Alex
Pamela
Anna
Andrew
Fred
Jack
James
Julie
Debby
Claudia
Matt
Brent
It uses the following list of domain names to compose the fake
address:
@aol.com
@hotmail.com
@yahoo.com
@msn.com
@excite.com
@mail.com
Killing processes
The worm kills processes if it finds any of the following
substrings in their names:
regedit
task
msconfig
AV
MC
Av
Mc
av
mc
IEFrame
nti
iru
ire
cc
ecu
can
scn
KV
fr
Payload
After December 1st, 2004, 01:01:01 the worm shuts down Windows on
an infected computer after its file is started. As a result a
user can not log in any more.
This worm variant is detected as 'I-Worm.Mydoom.w' since the
following FSAV updates:
[FSAV_Database_Version]
Version=2004-09-14_01
Technical Details:
Alexey Podrezov; September 20th, 2004;
F-Secure Corporation
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