F-Secure Virus Descriptions : Mimail.C
[Summary] | [Detailed Description]
|
|
THIS VIRUS IS RANKED AS LEVEL 2 ALERT UNDER
F-SECURE RADAR.
Radar Alert LEVEL 2
|
| NAME: | Mimail.C |
| ALIAS: | I-Worm.Mimail.c, W32/Mimail.C@mm, Mimail.C |
| ALIAS: | Bics, I-Worm.WatchNet |
Mimail.C worm was first found on 31st of October, 2003. The worm
spreads in e-mails as a ZIP archive that contains the worm's
executable with PHOTOS.JPG.EXE name. The worm tries to perform a
DoS (Denial of Service) attack on certain sites and to steal
information from infected computer users.
NOTE:
Shortly after Mimail.C was found, also D, E, F, G and H variants
have been found. They have minor differences and attack other web
sites. F-Secure Anti-Virus detects them too.
Descriptions of these Mimail variants can be found here:
Mimail.D:
http://www.europe.f-secure.com/v-descs/mimail_d.shtml
Mimail.E:
http://www.europe.f-secure.com/v-descs/mimail_e.shtml
Mimail.F:
http://www.europe.f-secure.com/v-descs/mimail_f.shtml
Mimail.G:
http://www.europe.f-secure.com/v-descs/mimail_g.shtml
Mimail.H:
http://www.europe.f-secure.com/v-descs/mimail_h.shtml
The worm's file is a PE executable 12832 bytes long packed with
UPX file compressor. The unpacked file's size is 28192 bytes.
Installation to system
When the worm's file is run, it registers itself as a service
process and becomes invisible in Task List on Windows 9x systems.
The the worm copies itself as NETWATCH.EXE file to Windows
directory and creates a startup key for this file in System
Registry:
[HKLM\Software\Microsoft\Windows\CurrentVersion\Run]
"NetWatch32" = "%windir%\netwatch.exe"
where %windir% is Windows directory name.
Then the worm deletes the following files from Windows folder if
they are present:
zip.tmp
exe.tmp
eml.tmp
After that the worm copies its file to Windows directory as
EXE.TMP and creates a ZIP archive with the name ZIP.TMP. This ZIP
archive contains the worm's copy with PHOTOS.JPG.EXE name.
The worm activates its payload and spreading theads if it can
resolve the 'www.google.com' address.
Spreading in e-mails
The worm spreads in e-mails as a ZIP archive that contains the
worm's executable with the PHOTOS.JPG.EXE name. The worm fakes
the sender's e-mail address by composing it from 'james@' and the
domain name of a recipient. An infected message looks like that:
From:
james@recipient_domain_name
Subject:
Re[2]: our private photos <some random characters>
Body:
Hello Dear!,
Finally i've found possibility to right u, my lovely girl :)
All our photos which i've made at the beach (even when u're without ur bh:))
photos are great! This evening i'll come and we'll make the best SEX :)
Right now enjoy the photos.
Kiss, James.
<some random characters>
Attachment:
photos.zip
The worm does not use any exploits to make its file start
automatically on a recipient's system. The worm will infect a
recipient's computer only when he/she unpacks the executable file
from the archive and runs it.
To collect victim's e-mail addresses the worm scans all files on
a hard drive except those with the following extensions:
bmp
jpg
gif
exe
dll
avi
mpg
mp3
vxd
ocx
psd
tif
zip
rar
pdf
cab
wav
com
The addresses are saved into the EML.TMP file located in Windows
directory.
The worm tries to contact the recipient's SMTP server directly.
For this purpose it tries to resolve the current user's DNS
server and search for SMTP server info for recipient's domain.
Payload
The worm tries to perform a DoS (Denial of Service) attack on the
following sites:
darkprofits.com
darkprofits.net
www.darkprofits.com
www.darkprofits.net
If the worm is widespread these sites may go down due to huge
traffic amount generated by the worm.
Additionally the worm checks foreground windows and if it locates
a window belonging to the certain application, the worm collects
certain information from it and saves it to C:\TMPE.TMP file.
Then this file is sent to e-mail addresses that are stored in an
encrypted form in the worm's body.
NOTE
Mimail.C was distributed in an Inor variant. Inor is a VBS
script that simply drops and runs a binary in c:\mware.exe
(Mimail.C). The distributed VBS arrives in email messages with:
Subject:
This is the Postfix program at host prodigy.com
I'm sorry to have to inform you that the message returned
below could not be delivered to one or more destinations.
The message itself and all the other important information
are included into the attachment.
Attachment:
undelivered.hta
Detection
Detection in F-Secure Anti-Virus was published on October 31st,
2003 in the following updates:
[FSAV_Database_Version]
Version=2003-10-31_01
Technical Details:
Alexey Podrezov and Katrin Tocheva; October 31st-November 3rd, 2003;
F-Secure Corporation
|
