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The Internet threat alert status is currently normal. At present, no major epidemics or other serious incidents have been recorded by Kaspersky Lab’s monitoring service. Internet threat level: 1

Trojan.Win32.Vilsel.ato

Detected Sep 10 2009 18:15 GMT
Released Sep 10 2009 22:35 GMT
Published Jul 02 2010 07:27 GMT

Manual description Auto description
This description was created by experts at Kaspersky Lab. It contains the most accurate information available about this program.

Technical Details
Payload
Removal instructions

Technical Details

This Trojan is designed to install and launch other malicious programs on the victim machine without the user’s knowledge or consent. It is a Windows PE EXE file. It is 1083904 bytes in size. It is packed by an unknown packer, with an unpacked size of approximately 2600 KB.


Payload

Disables the system firewall, changing the value of the following registry key:

[HKLM\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile] EnableFirewall=0
Tries to terminate processes that contain one of the strings listed below in their names:
AvSynMgr
naPrdMgr
vshwin32
McShield
mcshield
Mcdetect
mcagent
mcdash
mcvsshld
mcvsescn
mctskshd
MpfService
mcvs
opscan
ccapp
norton
SAVScan
ccApp
ccEvtMgr
ISSVC
SBServ
symlcsvc
SPBBCSvc
nod32krn
navapsvc
nava
nisum
nisserv
navwnt
AvpM
avpm
klswd
kav
kavsc avp.
AVGUARD
avguard
AVGNT
avgnt
sched
pavsrv51
AVENGINE
PNMSRV
PsImSvc
SRVLOAD
APVXDWIN
PavFnSvr
TPSrv
Inicio
pavcl
ntrtscan
OfcPfwSvc
PccNTMon
pccntupd
PNTIOMON
schupd
scan
fprot
avwin
ave32
isafe
tmntsrv
fsav32
avkwctl
ashServ
dvpapi
tsc
webtrap
TMOAgent
TeaTimer
sdhelper
Spybot
spybot
MSASCui
guard
ewido
avgas
avgemc
gcas
sunas
spys
ActiveDetection
blackd
fsdfwd
smc
zlclient
persfw
efpeadm
fsguiexe
kpf4gui
pccpfw

msscli
Tmas
swdoctor
spyc
ccsetmgr
ctagent
vsmon
webscan
dbgmgr
avp32
bdss
xcommsvr
avgamsvr
avfwsvc
avgupsvc
nvcpl
zonealarm
zlclient
scan
virus
firewall
protect
secure
optimize
nod32
mpf
agent
drweb
alert
avscan
kpf4
msblast
cfp
zapro
zonea
ave32
avp.
_av
When launched the Trojan is registered on the website of a cybercriminal, opening the following link:
http://fc.web********.de/as_noscript.php?name=load3
The program downloads a file from the following link:
http://fc.web********.de/as_noscript.php?name=rn
The downloaded file is then saved as follows:
%Temp%\<rnd>.tmp
where <rnd> is one of the following variants:
prun
rasesnet
wavvsnet
winvsnet
xpre
After it has been successfully downloaded it is executed and the Trojan clears the history of links in Internet Explorer and completes its operation.


Removal instructions

If your computer does not have an up-to-date antivirus program, or does not have an antivirus solution at all, follow the instructions below to delete the malicious program:

  1. Use Task Manager to terminate the malicious program’s process.
  2. Delete the original Trojan file (the location will depend on how the program originally penetrated the victim machine).
  3. Empty the temporary directory %Temp%.
  4. Restore system Firewall settings
  5. Update your antivirus databases and perform a full scan of the computer (download a trial version of Kaspersky Anti-Virus).


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Trojan

This type of behaviour covers malicious programs that delete, block, modify, or copy data, disrupt computer or network performance, but which cannot be classified under any of the behaviours identified above.

This classification also covers “multipurpose” Trojan programs, i.e. those that are capable of conducting several actions at once and which demonstrate several Trojan behaviours in a single program. This means they cannot be indisputably classified as having any single behaviour.


Aliases

Trojan.Win32.Vilsel.ato (Kaspersky Lab) is also known as:

  • Trojan: Generic Downloader.q (McAfee)
  • Mal/Generic-A (Sophos)
  • Generic Malware (Panda)
  • a variant of Win32/TrojanDownloader.Agent trojan (Nod32)
  • Trojan.Generic.1274872 (BitDef7)
  • Adware.Clicker.BA (VirusBuster)
  • Win32:Rootkit-gen [Rtk] (AVAST)
  • Trojan-Downloader.Agent (Ikarus)
  • Downloader.Generic8.LGN (AVG)
  • ADSPY/Clicker.DL (AVIRA)
  • Trojan.Dropper (NAV)
  • W32/DLoader.QEUN (Norman)
  • TROJ_DROPPER.FVK (TrendMicro)