Email-Worm:W32/Brontok.N

Classification

Malware

Email-Worm

W32

Email-Worm:W32/Brontok.N

Summary

VBS/Chick.A is a worm that is not considered to be a threat as the worm sends itself only once per infected system and only to a single recipient.

Removal

Automatic action

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

Suspect a file is incorrectly detected (a False Positive)?

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest detection database updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    NOTE If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note You need administrative rights to change the settings.

Find out more

Knowledge Base

Find the latest advice in our Community Knowledge Base.

User Guide

See the user guide for your product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details

Installation

After the worm's file is started, it copies itself with different names to different folders on a local hard drive. The file names can be semi-randomly generated or they can be any of the following:

  • csrss.exe
  • inetinfo.exe
  • lsass.exe
  • services.exe
  • smss.exe
  • winlogon.exe

Some of the worm's files have hidden, system, and read-only attributes. The worm can create its files with COM, EXE, and PIF extensions. Brontok worm creates multiple launch points for the copied files. Those include startup Registry keys as well as scheduled jobs. For example:

Status ID Day Time Command Line
 -------------------------------------------------------------------------------
 
1 Each M T W Th F S Su 5:08 PM "C:\Documents and Settings\User\Local Settings\Application Data\jalak-931976415-bali.com"
 
2 Each M T W Th F S Su 11:03 AM "C:\Documents and Settings\User\Local Settings\Application Data\jalak-931976415-bali.com"

Additionally, the worm creates a few text files on a local hard disk. The file named baca bro !!!.txt that is created in the root of the system drive has the following text:

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 ]
 

The c.bron.tok.txt file contains the following text:

  • Brontok.C
  • By:JowoBot

The worm keeps several copies of itself in memory.

Propagation

The worm sends messages with the following subjects:

  • Fotoku yg Paling Cantik
  • My Best Photo

The message body text can be one of the following:

Hi,
 Aku lg iseng aja pengen kirim foto ke kamu. Jangan lupain aku ya !. Thanks,
Hi,
 I want to share my photo with you. Wishing you all the best. Regards,

The attachment name is:

  • photo.zip

To collect email addresses to spread itself, the worm looks on drives from C: to Z for address in files with the following extensions:

  • .asp
  • .bat
  • .cfm
  • .com
  • .com
  • .csv
  • .doc
  • .eml
  • .exe
  • .htm
  • .html
  • .php
  • .pif
  • .ppt
  • .scr
  • .txt
  • .wab
  • .xls

The discovered addresses are checked against a rather large list of strings. If part of a discovered email address matches an entry in that list, that email address is discarded.The worm creates folders named Spread.Mail.Bro and Spread.Sent.Bro in one of its hidden subfolders. The first folder contains the list of email addresses that the worm harvested from the infected computer. Each email address is represented by a file that has the same text as the c.bron.tok.txt file (see above). When the worm sends an email to an address, the corresponding file is moved to the second folder. This is done to avoid sending the worm to the same address multiple times.

Payload

In addition to its propagation efforts, the worm has a rather old-fashioned effect. It can show the following texts in the command prompt window:

The effect is shown after the worm terminates applications that have the following text strings in their window titles:

  • ahnlab
  • alwil
  • anti
  • avg
  • avira
  • b.e
  • baca bro !!!
  • bitdef
  • BROWNIES
  • bugil
  • cewe
  • cillin
  • CLEANER
  • cmd.exe
  • command prompt
  • commander
  • computer management
  • ertanto
  • folder option
  • group policy
  • hijack
  • kaspersky
  • killbox
  • killer
  • mcafee
  • movzx
  • naked
  • nod32
  • norman
  • norton
  • pcmedia
  • pc-media
  • peid
  • porn
  • PROCESS EXP
  • registry
  • REMOVER
  • robknot
  • rontok
  • rontox
  • scheduled task
  • sex
  • symantec
  • SYSINTERNAL
  • system configuration
  • task manager
  • task view
  • telanjang
  • trendmicro
  • trojan
  • virus
  • washer
  • windows script
  • wintask
  • worm

The worm disables Task Manager, Registry Editor, and terminates applications that have the following text strings in their window titles:

  • ahnlab
  • aladdin
  • Alicia
  • Anti
  • ash
  • ashmaisv
  • aswupdsv
  • avast
  • avg
  • bitdef
  • ccapp
  • ccapps
  • cclaw
  • cillin
  • ctfmon
  • Dian
  • diary
  • dkernel
  • foto
  • grisoft
  • hijack
  • iexplorer
  • kangen
  • kaspersky
  • kill
  • lexplorer
  • machine
  • Mariana
  • mcaf
  • mcv
  • movzx
  • mspatch
  • nipsvc
  • njeeves
  • nod32
  • nopdb
  • norman
  • norton
  • nvcoas
  • opscan
  • panda
  • peid
  • poproxy
  • remove
  • riyani
  • Romantic
  • rontok
  • rontox
  • services.com
  • siti
  • sstray
  • symantec
  • sysinter
  • syslove
  • systray
  • trend
  • tskmgr
  • untukmu
  • update
  • virus
  • vptray
  • washer
  • wscript
  • xpshare
  • zlh

The worm modifies Windows HOSTS file to block access to the following domains:

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