Virus:Worm/Brontok.N.1
Date discovered:25/03/2006
Type:Worm
In the wild:No
Reported Infections:Low
Distribution Potential:Medium
Damage Potential:Medium
Static file:Yes
File size:43.520 Bytes
MD5 checksum:077fc28e71343d70bf08958b641be113
VDF version:6.34.00.97 - Saturday, March 25, 2006
IVDF version:6.34.00.97 - Saturday, March 25, 2006

 General Method of propagation:
   • Email


Aliases:
   •  Symantec: W32.Rontokbro.U@mm
   •  Kaspersky: Email-Worm.Win32.Brontok.n
   •  TrendMicro: WORM_RONTOKBR.AT
   •  Sophos: W32/Brontok-AE
   •  Bitdefender: Win32.Brontok.AF@mm


Platforms / OS:
   • Windows 95
   • Windows 98
   • Windows 98 SE
   • Windows NT
   • Windows ME
   • Windows 2000
   • Windows XP
   • Windows 2003


Side effects:
   • Blocks access to certain websites
   • Blocks access to security websites
   • Disable security applications
   • Downloads files
   • Uses its own Email engine
   • Lowers security settings
   • Registry modification


Right after execution the following information is displayed:



 Files It copies itself to the following locations:
   • %HOME%\Local Settings\Application Data\dv%several random digits%x\yesbron.com
   • %SYSDIR%\c_%several random digits%k.com
   • %SYSDIR%\n%several random digits%\csrss.exe
   • %SYSDIR%\n%several random digits%\smss.exe
   • %SYSDIR%\n%several random digits%\winlogon.exe
   • %SYSDIR%\n%several random digits%\services.exe
   • %SYSDIR%\n%several random digits%\sv%several random digits%.exe
   • %SYSDIR%\n%several random digits%\b%several random digits%.exe
   • %SYSDIR%\n%several random digits%\ib%several random digits%.exe
   • %WINDIR%\j%several random digits%.exe
   • %WINDIR%\o%several random digits%.exe
   • %WINDIR%\_default%several random digits%.pif
   • %HOME%\Local Settings\Application Data\jalak-%several random digits%-bali.com



It creates the following directories:
   • %SYSDIR%\n%several random digits%
   • %SYSDIR%\n%several random digits%\Spread.Mail.Bro
   • %SYSDIR%\n%several random digits%\Spread.Sent.Bro
   • %HOME%\Local Settings\Application Data\dv%several random digits%x



The following files are created:

– Files that contain collected email addresses:
   • %SYSDIR%\n%several random digits%\Spread.Mail.Bro\%collected email addresses%.ini
   • %SYSDIR%\n%several random digits%\Spread.Sent.Bro\%collected email addresses%.ini

– Temporary files that might be deleted afterwards:
   • %SYSDIR%\n%several random digits%\domlist.txt
   • %SYSDIR%\n%several random digits%\getdomlist.txt

– %system drive root%\Baca Bro !!!.txt This is a non malicious text file with the following content:
   • BRONTOK.C[22]
     Sedikit Jawaban u/ Membungkam Mulut Sesumbar 'MEREKA'.
     Nobron = Satria Dungu = Nothing !!!
     Romdil = Tukang Jiplak = Nothing !!!
     Nobron & Romdil -->> Kicked by The Amazing Brontok
     [ By JowoBot ]

– %SYSDIR%\n%several random digits%\c.bron.tok.txt This is a non malicious text file with the following content:
   • Brontok.C
     By:JowoBot

– %WINDIR%\tasks\at1.job File is a scheduled task that runs the malware at predefined times.
– %WINDIR%\tasks\at2.job File is a scheduled task that runs the malware at predefined times.



It tries to download some files:

– The location is the following:
   • http://www.net4free.org/Arts/bddwyrk/**********
It is saved on the local hard drive under: %SYSDIR%\n%several random digits%\sv%several random digits%r.exeupi22xbm.ini

– The location is the following:
   • http://debuging.com/WS1/cgi/**********
It is saved on the local hard drive under: %SYSDIR%\n%several random digits%\svt%number%sj.tok

 Registry The following registry key is added in order to run the process after reboot:

– [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   • "A%several random digits%r"="%WINDIR%\j%several random digits%.exe"



The values of the following registry keys are removed:

–  [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   • Adie Suka Kamu
   • Adie Strio X
   • SysYuni
   • SysDiaz
   • Sys_Romantic-Devil.R
   • SysRia
   • Pluto
   • DllHost
   • iExplorer
   • lExplorer
   • dkernel.exe
   • dkernel
   • Security
   • local service
   • SymRun
   • OSA
   • ccapp
   • CCAPPS
   • LoadServices
   • LoadService
   • MsPatch
   • Bron-Spizaetus-
   • Bron-Spizaetus-4713XPPM

–  [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   • Tok-Cirrhatus
   • Tok-Cirrhatus-%several random digits%adrc
   • Tok-Cirrhatus-%several random digits%

–  [HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]
   • NoFolderOptions

–  [HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\
   run]
   • Tok-Cirrhatus-%several random digits%adrc
   • brl



The following registry keys are added:

– [HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\
   run]
   • "y%several random digits%adr"="%user settings%\Application Data\dv%several random digits%x\yesbron.com"

– [HKCU\Software\Brontok]
   • "Version"="Brontok.C[22]"
   • "Developer"="JowoBot
   • VM Community"
   • "Released"="09-03-06"
   • "Message"=Look @ "C:\Baca Bro !!!.txt"
   • "Dedicated 2"="Spizaetus Cirrhatus"



The following registry keys are changed:

Disable Regedit and Task Manager:
– [HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System]
   Old value:
   • "DisableRegistryTools"=%user defined settings%
   New value:
   • "DisableRegistryTools"=dword:00000001

Various Explorer settings:
– [HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
   Old value:
   • "Hidden"=%user defined settings%
   • "HideFileExt"=%user defined settings%
   • "ShowSuperHidden"=%user defined settings%
   New value:
   • "Hidden"=dword:00000000
   • "HideFileExt"=dword:00000001
   • "ShowSuperHidden"=dword:00000000

– [HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot]
   Old value:
   • "AlternateShell"="cmd.exe"
   New value:
   • "AlternateShell"="c_%several random digits%k.com"

– [HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon]
   Old value:
   • "Shell"="Explorer.exe"
     "Userinit"="%SYSDIR%\userinit.exe"
   New value:
   • "Shell"=Explorer.exe "%WINDIR%\o%several random digits%.exe"
     "Userinit"="%SYSDIR%\userinit.exe,%WINDIR%\j%several random digits%.exe"

 Email It contains an integrated SMTP engine in order to send emails. A direct connection with the destination server will be established. The characteristics are described in the following:


From:
The sender of the email is one of the following:
   • jennifer_sh@%receiver's domain name from email address%
   • angelina_ph@%receiver's domain name from email address%


To:
– Email addresses found in specific files on the system.
– Generated addresses


Subject:
One of the following:
   • My Best Photo
   • Fotoku yg Paling Cantik



Body:
The body of the email is one of the following:

   • I want to share my photo with you.
     Wishing you all the best.
     Regards,

   • Aku lg iseng aja pengen kirim foto ke kamu.
     Jangan lupain aku ya !.
     Thanks,


Attachment:
The contents of the file is not a copy of itself but another malware. A description can be found here: TR/Dldr.Small.coc.1

The filename of the attachment is:
   • Picture.zip



The email looks like the following:


 Mailing Search addresses:
It searches the following files for email addresses:
   • PPT; XLS; CFM; PHP; ASP; WAB; EML; CSV; HTML; HTM; DOC; TXT


Avoid addresses:
It does not send emails to addresses containing one of the following strings:
   • BILLING@; INFO@; CONTOH; EXAMPLE; SMTP; XXX; TEST; NETWORK; SOURCE;
      PROGRAM; WWW; ASDF; SOME; YOUR; BLAH; SPAM; SOFT; PANDA; NORMAN;
      NORTON; ASSOCIATE; SYMANTEC; SECURITY; CILLIN; GRISOFT; AVG; LINUX;
      CRACK; HACK; VIRUS; MICROSOFT; MASTER; SUPPORT; SECURE; UPDATE;
      DEVELOP; VAKSIN; SATU; EMAILKU; BOLEH; GAUL; ASTAGA; .WEB.ID; .AC.ID;
      .OR.ID; .NET.ID; .SCH.ID; .MIL.ID; .GO.ID; .CO.ID; INDO; TELKOM; PLASA
      


MX Server:
It has the ability to contact one of the following MX servers:
   • ns1.
   • mail.
   • smtp.

 Hosts The host file is modified as explained:

– In this case existing entries are deleted.

– Access to the following domains is effectively blocked:
   • mcafee.com; www.mcafee.com; mcafee.net; www.mcafee.net; mcafee.org;
      www.mcafee.org; mcafeesecurity.com; www.mcafeesecurity.com;
      mcafeesecurity.net; www.mcafeesecurity.net; mcafeesecurity.org;
      www.mcafeesecurity.org; mcafeeb2b.com; www.mcafeeb2b.com;
      mcafeeb2b.net; www.mcafeeb2b.net; mcafeeb2b.org; www.mcafeeb2b.org;
      nai.com; www.nai.com; nai.net; www.nai.net; nai.org; www.nai.org;
      vil.nai.com; www.vil.nai.com; vil.nai.net; www.vil.nai.net;
      vil.nai.org; www.vil.nai.org; grisoft.com; www.grisoft.com;
      grisoft.net; www.grisoft.net; grisoft.org; www.grisoft.org;
      kaspersky-labs.com; www.kaspersky-labs.com; kaspersky-labs.net;
      www.kaspersky-labs.net; kaspersky-labs.org; www.kaspersky-labs.org;
      kaspersky.com; www.kaspersky.com; kaspersky.net; www.kaspersky.net;
      kaspersky.org; www.kaspersky.org; downloads1.kaspersky-labs.com;
      www.downloads1.kaspersky-labs.com; downloads1.kaspersky-labs.net;
      www.downloads1.kaspersky-labs.net; downloads1.kaspersky-labs.org;
      www.downloads1.kaspersky-labs.org; downloads2.kaspersky-labs.com;
      www.downloads2.kaspersky-labs.com; downloads2.kaspersky-labs.net;
      www.downloads2.kaspersky-labs.net; downloads2.kaspersky-labs.org;
      www.downloads2.kaspersky-labs.org; downloads3.kaspersky-labs.com;
      www.downloads3.kaspersky-labs.com; downloads3.kaspersky-labs.net;
      www.downloads3.kaspersky-labs.net; downloads3.kaspersky-labs.org;
      www.downloads3.kaspersky-labs.org; downloads4.kaspersky-labs.com;
      www.downloads4.kaspersky-labs.com; downloads4.kaspersky-labs.net;
      www.downloads4.kaspersky-labs.net; downloads4.kaspersky-labs.org;
      www.downloads4.kaspersky-labs.org; download.mcafee.com;
      www.download.mcafee.com; download.mcafee.net; www.download.mcafee.net;
      download.mcafee.org; www.download.mcafee.org; norton.com;
      www.norton.com; norton.net; www.norton.net; norton.org;
      www.norton.org; symantec.com; www.symantec.com; symantec.net;
      www.symantec.net; symantec.org; www.symantec.org;
      liveupdate.symantecliveupdate.com;
      www.liveupdate.symantecliveupdate.com;
      liveupdate.symantecliveupdate.net;
      www.liveupdate.symantecliveupdate.net;
      liveupdate.symantecliveupdate.org;
      www.liveupdate.symantecliveupdate.org; liveupdate.symantec.com;
      www.liveupdate.symantec.com; liveupdate.symantec.net;
      www.liveupdate.symantec.net; liveupdate.symantec.org;
      www.liveupdate.symantec.org; update.symantec.com;
      www.update.symantec.com; update.symantec.net; www.update.symantec.net;
      update.symantec.org; www.update.symantec.org;
      securityresponse.symantec.com; www.securityresponse.symantec.com;
      securityresponse.symantec.net; www.securityresponse.symantec.net;
      securityresponse.symantec.org; www.securityresponse.symantec.org;
      sarc.com; www.sarc.com; sarc.net; www.sarc.net; sarc.org;
      www.sarc.org; vaksin.com; www.vaksin.com; vaksin.net; www.vaksin.net;
      vaksin.org; www.vaksin.org; forum.vaksin.com; www.forum.vaksin.com;
      forum.vaksin.net; www.forum.vaksin.net; forum.vaksin.org;
      www.forum.vaksin.org; norman.com; www.norman.com; norman.net;
      www.norman.net; norman.org; www.norman.org; trendmicro.com;
      www.trendmicro.com; trendmicro.net; www.trendmicro.net;
      trendmicro.org; www.trendmicro.org; trendmicro-europe.com;
      www.trendmicro-europe.com; trendmicro-europe.net;
      www.trendmicro-europe.net; trendmicro-europe.org;
      www.trendmicro-europe.org; ae.trendmicro-europe.com;
      www.ae.trendmicro-europe.com; ae.trendmicro-europe.net;
      www.ae.trendmicro-europe.net; ae.trendmicro-europe.org;
      www.ae.trendmicro-europe.org; it.trendmicro-europe.com;
      www.it.trendmicro-europe.com; it.trendmicro-europe.net;
      www.it.trendmicro-europe.net; it.trendmicro-europe.org;
      www.it.trendmicro-europe.org; secunia.com; www.secunia.com;
      secunia.net; www.secunia.net; secunia.org; www.secunia.org;
      winantivirus.com; www.winantivirus.com; winantivirus.net;
      www.winantivirus.net; winantivirus.org; www.winantivirus.org;
      pandasoftware.com; www.pandasoftware.com; pandasoftware.net;
      www.pandasoftware.net; pandasoftware.org; www.pandasoftware.org;
      esafe.com; www.esafe.com; esafe.net; www.esafe.net; esafe.org;
      www.esafe.org; f-secure.com; www.f-secure.com; f-secure.net;
      www.f-secure.net; f-secure.org; www.f-secure.org; europe.f-secure.com;
      www.europe.f-secure.com; europe.f-secure.net; www.europe.f-secure.net;
      europe.f-secure.org; www.europe.f-secure.org; bhs.com; www.bhs.com;
      bhs.net; www.bhs.net; bhs.org; www.bhs.org; datafellows.com;
      www.datafellows.com; datafellows.net; www.datafellows.net;
      datafellows.org; www.datafellows.org; cheyenne.com; www.cheyenne.com;
      cheyenne.net; www.cheyenne.net; cheyenne.org; www.cheyenne.org;
      ontrack.com; www.ontrack.com; ontrack.net; www.ontrack.net;
      ontrack.org; www.ontrack.org; sands.com; www.sands.com; sands.net;
      www.sands.net; sands.org; www.sands.org; sophos.com; www.sophos.com;
      sophos.net; www.sophos.net; sophos.org; www.sophos.org; icubed.com;
      www.icubed.com; icubed.net; www.icubed.net; icubed.org;
      www.icubed.org; perantivirus.com; www.perantivirus.com;
      perantivirus.net; www.perantivirus.net; perantivirus.org;
      www.perantivirus.org; castlecops.com; www.castlecops.com;
      castlecops.net; www.castlecops.net; castlecops.org;
      www.castlecops.org; virustotal.com; www.virustotal.com;
      virustotal.net; www.virustotal.net; virustotal.org;
      www.virustotal.org; free-av.com; www.free-av.com; free-av.net;
      www.free-av.net; free-av.org; www.free-av.org; antivirus.com;
      www.antivirus.com; antivirus.net; www.antivirus.net; antivirus.org;
      www.antivirus.org; anti-virus.com; www.anti-virus.com; anti-virus.net;
      www.anti-virus.net; anti-virus.org; www.anti-virus.org; ca.com;
      www.ca.com; ca.net; www.ca.net; ca.org; www.ca.org; fajarweb.com;
      www.fajarweb.com; fajarweb.net; www.fajarweb.net; fajarweb.org;
      www.fajarweb.org; jasakom.com; www.jasakom.com; jasakom.net;
      www.jasakom.net; jasakom.org; www.jasakom.org; backup.grisoft.com;
      www.backup.grisoft.com; backup.grisoft.net; www.backup.grisoft.net;
      backup.grisoft.org; www.backup.grisoft.org; infokomputer.com;
      www.infokomputer.com; infokomputer.net; www.infokomputer.net;
      infokomputer.org; www.infokomputer.org; playboy.com; www.playboy.com;
      playboy.net; www.playboy.net; playboy.org; www.playboy.org;
      sex-mission.com; www.sex-mission.com; sex-mission.net;
      www.sex-mission.net; sex-mission.org; www.sex-mission.org;
      pornstargals.com; www.pornstargals.com; pornstargals.net;
      www.pornstargals.net; pornstargals.org; www.pornstargals.org;
      kaskus.com; www.kaskus.com; kaskus.net; www.kaskus.net; kaskus.org;
      www.kaskus.org; 17tahun.com; www.17tahun.com; 17tahun.net;
      www.17tahun.net; 17tahun.org; www.17tahun.org; padinet.com;
      www.padinet.com; padinet.net; www.padinet.net; padinet.org;
      www.padinet.org; jeruk.padinet.com; www.jeruk.padinet.com;
      jeruk.padinet.net; www.jeruk.padinet.net; jeruk.padinet.org;
      www.jeruk.padinet.org; compactbyte.com; www.compactbyte.com;
      compactbyte.net; www.compactbyte.net; compactbyte.org;
      www.compactbyte.org; blog.compactbyte.com; www.blog.compactbyte.com;
      blog.compactbyte.net; www.blog.compactbyte.net; blog.compactbyte.org;
      www.blog.compactbyte.org; blogs.compactbyte.com;
      www.blogs.compactbyte.com; blogs.compactbyte.net;
      www.blogs.compactbyte.net; blogs.compactbyte.org;
      www.blogs.compactbyte.org




The modified host file will look like this:


 Process termination Processes with one of the following strings are terminated:
   • ahnlab; peid; nod32; hijack; sysinter; aladdin; panda; trend; cillin;
      mcaf; avast; bitdef; machine; movzx; kill; washer; remove; wscript;
      diary; untukmu; kangen; sstray; Alicia; Mariana; Dian; foto; zlh;
      Anti; mspatch; siti; virus; services.com; ctfmon; nopdb; opscan;
      vptray; update; lexplorer; iexplorer; nipsvc; njeeves; cclaw; nvcoas;
      aswupdsv; ashmaisv; systray; riyani; xpshare; syslove; tskmgr; ccapps;
      ash; avg; poproxy; mcv

Processes containing one of the following window titles are terminated:
   • peid; task view; telanjang; bugil; cewe; naked; porn; sex; alwil;
      wintask; folder option; b.e; worm; trojan; avira; windows script;
      commander; pc-media; killer; ertanto; anti; CLEANER; REMOVER; PROCESS
      EXP; SYSINTERNAL; killbox; scheduled task; computer management;
      cmd.exe; group policy; system configuration; command prompt; registry;
      baca bro !!!; task manager; google.com; up22ngk
      


 File details Programming language:
 The malware program was written in MS Visual C++.


Runtime packer:
In order to aggravate detection and reduce size of the file it is packed with a runtime packer.

Description inserted by Adriana Popa on Tuesday, July 25, 2006
Description updated by Andrei Gherman on Wednesday, July 26, 2006

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