WORM_DORKBOT.TKF

 Analysis by: Anthony Joe Melgarejo

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Propagates via removable drives

This worm arrives via removable drives. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

It runs certain commands that it receives remotely from a malicious user. Doing this puts the affected computer and information found on the computer at greater risk. It connects to a website to send and receive information.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

947,200 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

06 Oct 2012

Payload:

Connects to URLs/IPs, Steals information, Compromises system security, Downloads files

Arrival Details

This worm arrives via removable drives.

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This worm drops the following copies of itself into the affected system:

  • %User Profile%\Application Data\{6 random characters}.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • 470a1245
  • dontfuckwithmekk
  • whatwhatinthebuttsdfg345gersdf345dghe54645

It injects threads into the following normal process(es):

  • explorer.exe
  • winlogon.exe

Autostart Technique

This worm adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{6 random characters} = "%User Profile%\Application Data\{6 random characters}.exe"

Propagation

This worm drops the following copy(ies) of itself in all removable drives:

  • {drive letter}:\RECYCLER\470a1245.exe

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

[AutoRun]
;{garbage characters}
shellexecute=RECYCLER\470a1245.exe
;{garbage characters}
icon=shell32.dll,7
;{garbage characters}
shell\open\command=RECYCLER\470a1245.exe
;{garbage characters}
action=Open folder to view files
;{garbage characters}
shell\explore\command=RECYCLER\470a1245.exe
;{garbage characters}
useautoplay=1

Backdoor Routine

This worm executes the following command(s) from a remote malicious user:

  • Block DNS
  • Create processes
  • Download other files
  • Insert iframe tags into HTML files
  • Join an IRC channel
  • Log in to FTP sites
  • Perfrom Slowloris, UDP, and SYN flooding
  • Run Reverse Socks4 proxy server
  • Send MSN Messenger messages
  • Steal login credentials
  • Update Itself
  • Visit a Web Site

It connects to the following websites to send and receive information:

  • {BLOCKED}48.com:443
  • {BLOCKED}1.com:443
  • {BLOCKED}4.com:443
  • {BLOCKED}25.com:443

Download Routine

This worm accesses the following websites to download files:

  • http://up.{BLOCKED}es.com/uploads/28_12_1213566658223.png

It saves the files it downloads using the following names:

  • %User Profile%\Application Data\{random number}.exe - detected as TROJ_BITCOIN.TKF

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Other Details

This worm connects to the following URL(s) to get the affected system's IP address:

  • http://api.wipmania.com/

It deletes itself after execution.

NOTES:

It monitors the user's browsing activities. It gathers the user's login ID, password and email when the site accessed by the user contains the following strings:

  • *.moneybookers.*/*login.pl
  • *1and1.com/xml/config*
  • *4shared.com/login*
  • *:2082/login*
  • *:2083/login*
  • *:2086/login*
  • *:2222/CMD_LOGIN*
  • *FLN-Password=*
  • *LoginPassword=*
  • *Passwd=*
  • *Password=*
  • *TextfieldPassword=*
  • *alertpay.com/login*
  • *aol.*/*login.psp*
  • *bcointernacional*login*
  • *bebo.*/c/home/ajax_post_lifestream_comment
  • *bebo.*/c/profile/comment_post.json
  • *bebo.*/mail/MailCompose.jsp*
  • *bigstring.*/*index.php*
  • *clave=*
  • *depositfiles.*/*/login*
  • *dotster.com/*login*
  • *dyndns*/account*
  • *enom.com/login*
  • *facebook.*/ajax/*MessageComposerEndpoint.php*
  • *facebook.*/ajax/chat/send.php*
  • *facebook.*/login.php*
  • *fastmail.*/mail/*
  • *fileserv.com/login*
  • *filesonic.com/*login*
  • *freakshare.com/login*
  • *friendster.*/rpc.php
  • *friendster.*/sendmessage.php*
  • *gmx.*/*FormLogin*
  • *godaddy.com/login*
  • *google.*/*ServiceLoginAuth*
  • *hackforums.*/member.php
  • *hotfile.com/login*
  • *letitbit.net*
  • *login.live.*/*post.srf*
  • *login.yahoo.*/*login*
  • *loginUserPassword=*
  • *login_password=*
  • *mediafire.com/*login*
  • *megaupload.*/*login*
  • *members*.iknowthatgirl*/members*
  • *members.brazzers.com*
  • *moniker.com/*Login*
  • *namecheap.com/*login*
  • *netflix.com/*ogin*
  • *netload.in/index*
  • *officebanking.cl/*login.asp*
  • *oron.com/login*
  • *paypal.*/webscr?cmd=_login-submit*
  • *runescape*/*weblogin*
  • *screenname.aol.*/login.psp*
  • *secure.logmein.*/*logincheck*
  • *sendspace.com/login*
  • *service=youtube*
  • *signin.ebay*SignIn
  • *sms4file.com/*/signin-do*
  • *speedyshare.com/login*
  • *steampowered*/login*
  • *thepiratebay.org/login*
  • *torrentleech.org/*login*
  • *twitter.*/*direct_messages/new*
  • *twitter.*/*status*/update*
  • *twitter.com/sessions
  • *uploaded.to/*login*
  • *uploading.com/*login*
  • *vip-file.com/*/signin-do*
  • *vkontakte.ru/api.php
  • *vkontakte.ru/mail.php
  • *vkontakte.ru/wall.php
  • *webnames.ru/*user_login*
  • *what.cd/login*
  • *whcms*dologin*
  • *youporn.*/login*

It attempts to steal user credentials used in the following websites:

  • 1and1
  • 4shared
  • Alertpay
  • Bcointernacional
  • Bebo
  • BigString
  • Brazzers
  • Clave
  • Depositfiles
  • Dotster
  • DynDNS
  • Ebay
  • Email
  • FLN-Password
  • FLN-UserName
  • Facebook
  • Fastmail
  • Fileserve
  • Filesonic
  • Freakshare
  • Friendster
  • Gmail
  • Godaddy
  • Hackforums
  • Hotfile
  • IKnowThatGirl
  • Letitbit
  • LogMeIn
  • Mediafire
  • Megaupload
  • Message
  • Moneybookers
  • Moniker
  • Namecheap
  • Netflix
  • Netload
  • OfficeBanking
  • Passwd
  • PayPal
  • Runescape
  • Sendspace
  • Sms4file
  • Speedyshare
  • Steam
  • Thepiratebay
  • Torrentleech
  • Twitter
  • Uploaded
  • Uploading.com
  • Vip-file
  • Vkontakte
  • Webnames
  • Whatcd
  • Yahoo
  • YouPorn
  • YouTube

It may also prevent the user from using the following applications:

  • cmd.exe
  • ipconfig.exe
  • regedit.exe
  • regsvr32.exe
  • rundll32.exe
  • verclsid.exe

It drops shortcut (.LNK) files named after the folders found in the removable drives pointing to the copy of itself in the removable drives. It sets the folders' file attribute to Hidden.

It sends messages that contain links to sites hosting remote copies of itself using the following instant messaging (IM) applications:

  • MSN Messenger
  • mIRC

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.622.06

FIRST VSAPI PATTERN DATE:

28 Dec 2012

VSAPI OPR PATTERN File:

9.623.00

VSAPI OPR PATTERN Date:

29 Dec 2012

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Remove malware/grayware files dropped/downloaded by WORM_DORKBOT.TKF

  • TROJ_BITCOIN.TKF

Step 3

Scan your computer with your Trend Micro product and note files detected as WORM_DORKBOT.TKF

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {6 random characters} = "%User Profile%\Application Data\{6 random characters}.exe"

Step 6

Search and delete AUTORUN.INF files created by WORM_DORKBOT.TKF that contain these strings

[ Learn More ]
[autorun]
;{garbage characters}
shellexecute=RECYCLER\470a1245.exe
;{garbage characters}
icon=shell32.dll,7
;{garbage characters}
shell\open\command=RECYCLER\470a1245.exe
;{garbage characters}
action=Open folder to view files
;{garbage characters}
shell\explore\command=RECYCLER\470a1245.exe
;{garbage characters}
useautoplay=1

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_DORKBOT.TKF. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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