Analysis by: Rika Joi Gregorio
ALIASES:

Worm:Win32/Dorkbot.I(Microsoft), Trojan-Ransom.Win32.Foreign(Ikarus), Downloader-FRG!C14E353386BE(McAfee), Win32/Dorkbot.B worm(Eset)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Propagates via flashdrives, Downloaded from the Internet, Dropped by other malware, Via social networking sites

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 executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size: 157,696 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 09 Oct 2014
Payload: Compromises system security, Steals information

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 files:

  • {Drive Letter}:\{Folder/File Name}.lnk

It drops the following copies of itself into the affected system:

  • %Application Data%\ScreenSaverPro.scr
  • %Application Data%\temp.bin

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It adds the following processes:

  • svchost.exe
  • mspaint.exe

It injects itself into the following processes as part of its memory residency routine:

  • created svchost.exe
  • created mspaint.exe
  • winlogon.exe
  • explorer.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
Screen Saver Pro 3.1 = "%Application Data%\ScreenSaverPro.scr"

Propagation

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

  • {Drive Letter}:\{random}.exe

It propagates via the following social networking sites:

  • Bebo - via comments and messages
  • Friendster - via messages, comments, shoutouts, chat
  • Twitter - via tweets and direct messages
  • Facebook - via messages, chats, and status messages

Backdoor Routine

This worm executes the following commands 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 URL(s) to send and receive commands from a remote malicious user:

  • a.{BLOCKED}22.ru
  • a.{BLOCKED}222.com
  • a.{BLOCKED}2.com

Other Details

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

  • http://api.wipmania.com/
  • http://app.wipmania.net/icon/n.api

NOTES:

This worm 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 drops shortcut (.LNK) files named after the folders/files found in the removable drives which points to the copy of itself in the removable drives. The target property of the .LNK files is the following:

%ALLUSERSPROFILE%\..\..\windows\system32\cmd.exe /c "start %cd%{file/folder name} & start %cd%{random}.exe & exit"

It then sets the folders' attribute to HIDDEN.

It monitors if browser accesses URLs with following strings:

  • avast
  • avira
  • bitdefender
  • bullguard
  • clamav
  • comodo
  • emsisoft
  • eset
  • f-secure
  • fortinet
  • garyshood
  • gdatasoftware
  • heck.tc
  • iseclab
  • jotti
  • kaspersky
  • lavasoft
  • malwarebytes
  • mcafee
  • norman
  • norton
  • novirusthanks
  • nprotect
  • onecare.live
  • onlinemalwarescanner
  • pandasecurity
  • precisesecurity
  • sophos
  • sunbeltsoftware
  • symantec
  • threatexpert
  • trendmicro
  • virscan
  • virus
  • virusbuster
  • viruschief
  • virustotal
  • webroot

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.200.07
FIRST VSAPI PATTERN DATE: 10 Oct 2014
VSAPI OPR PATTERN File: 11.201.00
VSAPI OPR PATTERN Date: 10 Oct 2014

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.YBA. (Note: Please skip this step if the threats listed below have already been removed.)

    • LNK_DORKBOT.WRF
    • TROJ_LETHIC.WRF

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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
    • Screen Saver Pro 3.1 = "%Application Data%\ScreenSaverPro.scr"

Step 5

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • {Drive Letter}:\ViewFiles.lnk
  • {Drive Letter}:\{Folder/File Name}.lnk

Step 6

Scan your computer with your Trend Micro product to delete files detected as WORM_DORKBOT.YBA. 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.

Step 7

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