WORM_DORKBOT.DN

 Analysis by: Cris Nowell Pantanilla

 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

To get a one-glance comprehensive view of the behavior of this Worm, refer to the Threat Diagram shown below.

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 copies of itself in all removable drives. 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.

  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\{random}.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 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
{random} = "%User Profile%\Application Data\{random}.exe"

Propagation

This worm drops copies of itself in all removable drives.

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\{random characters}.exe
;{garbage characters}
icon=shell32.dll,7
;{garbage characters}
shell\open\command=RECYCLER\{random characters}.exe
;{garbage characters}
action=Open folder to view files
;{garbage characters}
shell\explore\command=RECYCLER\{random characters}.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
  • Perform 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:

  • ok77548.com
  • ca98741.com
  • zuf174.com
  • 1k4j25.com

Download Routine

This worm accesses the following websites to download files:

  • http://up.arabseyes.com/uploads/28_12_1213566658223.png

It saves the files it downloads using the following names:

  • %User Profile%\Application Data\{random number}.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.)

Trend Micro detects the dowloaded file as:

  • WORM_DORKBOT.IF

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/

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 sites:

  • 1and1
  • 4shared
  • AlertPay
  • Bco Internacional
  • Bebo
  • BigString
  • Brazzers
  • Clave
  • DepositFiles
  • Dotster
  • DynDNS
  • eBay
  • Email
  • FLN-Password
  • FLN-UserName
  • Facebook
  • FastMail
  • FileServe
  • FileSonic
  • FreakShare
  • Friendster
  • Gmail
  • Go Daddy
  • Hack Forums
  • Hotfile
  • IKnowThatGirl
  • Letitbit
  • LogMeIn
  • MediaFire
  • Megaupload
  • Message
  • Moneybookers
  • Moniker
  • Namecheap
  • Netflix
  • Netload
  • OfficeBanking
  • Passwd
  • PayPal
  • Runescape
  • SendSpace
  • Sms4file
  • SpeedyShare
  • Steam
  • The Pirate Bay
  • TorrentLeech
  • Twitter
  • Uploaded
  • Uploading.com
  • Vip-file
  • Vkontakte
  • Webnames
  • Whatcd
  • Yahoo
  • YouPorn
  • YouTube

It has the following backdoor capabilities:

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

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 a shortcut file named "RECYCLER" pointing to the copy of itself in removable drives.

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

  • mIRC
  • MSN Messenger

  SOLUTION

Minimum Scan Engine:

9.300

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.DN

Step 3

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

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
    • {random} = "%User Profile%\Application Data\{random}.exe"

Step 6

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

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

Step 7

Search and delete the file detected as WORM_DORKBOT.DN

[ Learn More ]

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_DORKBOT.DN. 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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