WORM_KELIHOS.TSH

 Analysis by: Rika Joi Gregorio

 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:

Downloaded from the Internet, Dropped by other malware

This worm 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. It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size:

1,206,237 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

28 Aug 2013

Payload:

Steals information, Compromises system security

Arrival Details

This worm 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 and executes them:

  • {random directory}\{random file name 1}

It drops the following files:

  • {Drive Letter}:\Shortcut to {random file name 2}.lnk
  • {Drive Letter}:\{Folder name}.lnk - points to malware copy {Drive Letter}:\{random file name 2}.exe

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{random parameter 1}{random parameter 2} = "{random directory}\{random file name 1}"

Other System Modifications

This worm adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
DefaultCompressedRecord = "{random value}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
RecordModifiedMax = "{random value}=="

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
FlagsModifiedValid = "0"

HKEY_CURRENT_USER\Software\TansuTCP
ActiveModifiedTheme = "{random value}"

HKEY_CURRENT_USER\Software\TansuTCP
SizeCompletedValid = "{random value}=="

HKEY_CURRENT_USER\Software\TansuTCP
InfoPlayedCurrent = "0"

Propagation

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

  • {Drive Letter}:\{random file name 2}.exe

Backdoor Routine

This worm executes the following commands from a remote malicious user:

  • Request spam email messages structure and template
  • Send spam email messages
  • Send stolen information
  • Get operating system information
  • Get drive information
  • List running processes
  • Download and execute arbitrary files
  • Update server with a list of compromised computers
  • Manage registry
  • Download updated copy of itself

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

  • http://{BLOCKED}.{BLOCKED}.92.60/index.htm
  • http://{BLOCKED}.{BLOCKED}.92.60/install.htm
  • http://{BLOCKED}.{BLOCKED}.29.191/index.htm
  • http://{BLOCKED}.{BLOCKED}.29.191/search.htm
  • http://{BLOCKED}.{BLOCKED}.99.41/default.htm
  • http://{BLOCKED}.{BLOCKED}.99.41/index.htm
  • http://{BLOCKED}.{BLOCKED}.99.47/default.htm
  • http://{BLOCKED}.{BLOCKED}.99.47/index.htm
  • http://{BLOCKED}.{BLOCKED}.26.213/home.htm
  • http://{BLOCKED}.{BLOCKED}.26.213/install.htm
  • http://{BLOCKED}.{BLOCKED}.41.85/defaul .htm
  • http://{BLOCKED}.{BLOCKED}.41.85/install.htm
  • http://{BLOCKED}.{BLOCKED}.50.176/install.htm
  • http://{BLOCKED}.{BLOCKED}.50.176/online.htm
  • http://{BLOCKED}.{BLOCKED}.50.176/search.htm
  • http://{BLOCKED}.{BLOCKED}.50.176/setup.htm
  • http://{BLOCKED}.{BLOCKED}.199.75/main.htm
  • http://{BLOCKED}.{BLOCKED}.199.75/search.htm
  • http://{BLOCKED}.{BLOCKED}.252.113/online.htm
  • http://{BLOCKED}.{BLOCKED}.252.113/setup.htm
  • http://{BLOCKED}.{BLOCKED}.101.47/default.htm
  • http://{BLOCKED}.{BLOCKED}.101.47/start.htm
  • http://{BLOCKED}.{BLOCKED}.245.128/online.htm
  • http://{BLOCKED}.{BLOCKED}.245.128/welcome.htm
  • http://{BLOCKED}.{BLOCKED}.43.230/default.htm
  • http://{BLOCKED}.{BLOCKED}.43.230/file.htm
  • http://{BLOCKED}.{BLOCKED}.79.46/default.htm
  • http://{BLOCKED}.{BLOCKED}.79.46/start.htm
  • http://{BLOCKED}.{BLOCKED}.152.225/default.htm
  • http://{BLOCKED}.{BLOCKED}.152.225/online.htm
  • http://{BLOCKED}.{BLOCKED}.43.85/search.htm
  • http://{BLOCKED}.{BLOCKED}.43.85/index.htm
  • http://{BLOCKED}.{BLOCKED}.65.82/welcome.htm
  • http://{BLOCKED}.{BLOCKED}.65.82/default.htm

Information Theft

This worm attempts to steal stored account information used in the following installed File Transfer Protocol (FTP) clients or file manager software:

  • 32BitFTP
  • 3D-FTP
  • ALFTP
  • AceBIT
  • BitKinex
  • BlazeFtp
  • BulletProof FTP
  • ClassicFTP
  • CoffeeCup Software
  • Core FTP
  • Cyberduck
  • DeluxeFTP
  • Directory Opus
  • EasyFTP
  • FTPNow
  • FarManager
  • FastStone FTP
  • FFFTP
  • FileZilla
  • FlashFXP
  • Fling FTP
  • FreshFTP
  • FTPGetter
  • FTP Commander
  • FTP Control
  • FTP Explorer
  • FTP Navigator
  • FTP Surfer
  • FTPRush
  • FTPShell
  • GlobalSCAPE CuteFTP 6 Home
  • GlobalSCAPE CuteFTP 6 Professional
  • GlobalSCAPE CuteFTP
  • GlobalSCAPE CuteFTP 7 Home
  • GlobalSCAPE CuteFTP 7 Professional
  • GlobalSCAPE CuteFTP 8 Home
  • GlobalSCAPE CuteFTP 8 Professional
  • GlobalSCAPE CuteFTP Lite
  • GlobalSCAPE CuteFTP Pro
  • KiTTY
  • LeapWare
  • LeechFTP
  • LinasFTP
  • MAS-Soft FTPInfo
  • My FTP
  • NetDrive
  • NetSarang
  • NexusFile
  • NovaFTP
  • NppFTP
  • PuTTY
  • Quick FTP
  • Robo-FTP
  • SecureFX
  • SmartFTP
  • SoftX FTP Client
  • Total Commander
  • TurboFTP
  • UltraFXP
  • WebDrive
  • WebSitePublisher
  • WinFTP
  • WinSCP
  • WS_FTP

It gathers the following account information from any of the mentioned File Transfer Protocol (FTP) clients or file manager software:

  • Server Name
  • User Name
  • Password
  • Directory
  • Port

It attempts to get stored information such as user names, passwords, and hostnames from the following browsers:

  • Bromium
  • ChromePlus
  • Chromium
  • Comodo
  • CoolNovo
  • Epic Browser
  • Google Chrome
  • K-Meleon
  • Nichrome
  • Rockmelt
  • Yandex

NOTES:

This worm modifies its file attributes to Read-only and Hidden after execution.

It drops copies of itself as {random file name 1} with the following file names in different directories:

  • acrord32
  • agent
  • ati2evxx
  • avguard
  • batch
  • block
  • ccapp
  • ccevtmgr
  • ccsetmgr
  • convert
  • decompile
  • defwatch
  • download
  • em_exec
  • explorer
  • extract
  • ezsp_px
  • firefox
  • gearsec
  • hkcmd
  • htpatch
  • ielowutil
  • ieuser
  • iexplore
  • igfxtray
  • isuspm
  • jucheck
  • jusched
  • khalmnpr
  • klwtblfs
  • launch
  • lsass
  • lucoms
  • mcshield
  • mcvsescn
  • msascui
  • mscorsvw
  • mspmspsv
  • naprdmgr
  • navapsvc
  • nprotect
  • ntvdm
  • nvsvc32
  • nvxdsync
  • pctspk
  • pdvddxsrv
  • point32
  • qbw32
  • qttask
  • rename
  • rundll32
  • services
  • sidebar
  • spoolsv
  • svchost
  • taskman
  • terraria
  • toaster
  • trustedinstaller
  • umodrive
  • unhide
  • unpack
  • unzip
  • update
  • upgrade
  • uptime
  • vsmon
  • webscanx
  • winlogon
  • wisptis
  • wmpnetwk
  • wmpnscfg
  • zcfgsvc

The dropped copy, {random file name 2} in removable drives can be any of the following:

  • click
  • game
  • hentai
  • installer
  • password
  • porn
  • run
  • sas
  • screensaver

It drops shortcut files pointing to the copy of itself in removable drives. These dropped .LNK files use the names of the folders located on the said drives for their file names. It then sets the attributes of the original folders to Hidden to trick the user into clicking the .LNK files.

The auto-run registry, {random parameter 1} can be any of the following:

  • Network
  • Time
  • CrashReport
  • Database
  • Icon
  • Desktop
  • Tray
  • Video
  • Media

The auto-run registry, {random parameter 2} can be any of the following:

  • Checker
  • Informer
  • Notifyer
  • Saver
  • Updater
  • Verifyer

For example:

  • NetworkVerifyer
  • TrayNotifyer
  • CrashReportUpdater

It monitors network traffic to acquire data from E-mail and FTP accounts using the following strings:

  • AUTH_PLAIN
  • Authorization
  • Basic
  • CONNECT
  • PASS
  • USER
  • pop3_smtp

It exchanges encrypted messages with a remote server via HTTP protocol (TCP port 80). It uses the following crafted User-Agent when communicating with the remote host:

  • Mozilla/5.0 (Windows NT 5.1) Gecko/20100101 Firefox/14.0 Opera/12.0
  • Opera/9.80 (Windows NT 5.1; U; zh-sg) Presto/2.9.181 Version/12.00
  • Opera/9.80 (Windows NT 6.1; U; es-ES) Presto/2.9.181 Version/12.00
  • Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.0) Opera 12.14
  • Mozilla/5.0 (Windows NT 6.0; rv:2.0) Gecko/20100101 Firefox/4.0 Opera 12.14
  • Opera/9.80 (Windows NT 6.0) Presto/2.12.388 Version/12.14
  • Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_7; da-dk) AppleWebKit/533.21.1 (KHTML, like Gecko) Version/5.0.5 Safari/533.21.1
  • Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_8; de-at) AppleWebKit/533.21.1 (KHTML, like Gecko) Version/5.0.5 Safari/533.21.1
  • Mozilla/5.0 (iPad; CPU OS 5_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko ) Version/5.1 Mobile/9B176 Safari/7534.48.3
  • Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_3) AppleWebKit/534.55.3 (KHTML, like Gecko) Version/5.1.3 Safari/534.53.10
  • Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/537.13+ (KHTML, like Gecko) Version/5.1.7 Safari/534.57.2
  • Mozilla/5.0 (iPad; CPU OS 6_0 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) Version/6.0 Mobile/10A5355d Safari/8536.25
  • Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0; chromeframe/12.0.742.112)
  • Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; Media Center PC 6.0; InfoPath.3; MS-RTC LM 8; Zune 4.7)
  • Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 7.1; Trident/5.0)
  • Mozilla/5.0 (Windows; U; MSIE 9.0; Windows NT 9.0; en-US)
  • Mozilla/1.22 (compatible; MSIE 10.0; Windows 3.1)
  • Mozilla/4.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/5.0)
  • Mozilla/5.0 (compatible; MSIE 10.0; Macintosh; Intel Mac OS X 10_7_3; Trident/6.0)
  • Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/4.0; InfoPath.2; SV1; .NET CLR 2.0.50727; WOW64)
  • Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/5.0)
  • Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/6.0)
  • Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0)
  • Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:21.0) Gecko/20100101 Firefox/21.0
  • Mozilla/5.0 (Windows NT 5.0; rv:21.0) Gecko/20100101 Firefox/21.0
  • Mozilla/5.0 (Windows NT 5.1; rv:21.0) Gecko/20100101 Firefox/21.0
  • Mozilla/5.0 (Windows NT 5.1; rv:21.0) Gecko/20130331 Firefox/21.0
  • Mozilla/5.0 (Windows NT 5.1; rv:21.0) Gecko/20130401 Firefox/21.0
  • Mozilla/5.0 (Windows NT 6.1; rv:21.0) Gecko/20100101 Firefox/21.0
  • Mozilla/5.0 (Windows NT 6.1; rv:21.0) Gecko/20130328 Firefox/21.0
  • Mozilla/5.0 (Windows NT 6.1; rv:21.0) Gecko/20130401 Firefox/21.0
  • Mozilla/5.0 (Windows NT 6.1; WOW64; rv:21.0) Gecko/20100101 Firefox/21.0
  • Mozilla/5.0 (Windows NT 6.1; WOW64; rv:21.0) Gecko/20130330 Firefox/21.0
  • Mozilla/5.0 (Windows NT 6.1; WOW64; rv:21.0) Gecko/20130331 Firefox/21.0
  • Mozilla/5.0 (Windows NT 6.1; WOW64; rv:21.0) Gecko/20130401 Firefox/21.0
  • Mozilla/5.0 (Windows NT 6.2; rv:21.0) Gecko/20130326 Firefox/21.0
  • Mozilla/5.0 (X11; Linux i686; rv:21.0) Gecko/20100101 Firefox/21.0
  • Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:21.0) Gecko/20100101 Firefox/21.0
  • Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:21.0) Gecko/20130331 Firefox/21.0
  • Mozilla/5.0 (Windows NT 6.1; rv:22.0) Gecko/20130405 Firefox/22.0
  • Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:22.0) Gecko/20130328 Firefox/22.0
  • Mozilla/5.0 (Windows NT 6.2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1464.0 Safari/537.36
  • Mozilla/5.0 (Windows NT 6.2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1467.0 Safari/537.36
  • Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1468.0 Safari/537.36
  • Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.2 Safari/537.36
  • Mozilla/5.0 (compatible; MSIE 9.0; AOL 9.7; AOLBuild 4343.19; Windows NT 6.1; WOW64; Trident/5.0; FunWebProducts)
  • Mozilla/5.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; Acoo Browser 1.98.744; .NET CLR 3.5.30729)

It also attempts to steal information from %Application Data%\Bitcoin\wallet.dat.

It sends spammed email messages using Simple Mail Transfer Protocol (SMTP) connection.

It also has the capability to get a new list of IP addresses from its C&C server. The list of addresses may change depending on the malware author.

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

10.246.01

FIRST VSAPI PATTERN DATE:

29 Aug 2013

VSAPI OPR PATTERN File:

10.247.00

VSAPI OPR PATTERN Date:

30 Aug 2013

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

Scan your computer with your Trend Micro product and note files detected as WORM_KELIHOS.TSH

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\Explorer\Advanced
    • DefaultCompressedRecord = "{random value}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • RecordModifiedMax = "{random value}=="
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • FlagsModifiedValid = "0"
  • In HKEY_CURRENT_USER\Software\TansuTCP
    • ActiveModifiedTheme = "{random value}"
  • In HKEY_CURRENT_USER\Software\TansuTCP
    • SizeCompletedValid = "{random value}=="
  • In HKEY_CURRENT_USER\Software\TansuTCP
    • InfoPlayedCurrent = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • {random parameter 1}{random parameter 2} = "{random directory}\{random file name 1}"

Step 5

Search and delete these files

[ Learn More ]
There may be some component 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}:\Shortcut to {random file name 2}.lnk
  • {Drive Letter}:\{Folder name}.lnk

Step 6

Search and delete the files detected as WORM_KELIHOS.TSH

*Note: Some component files may be 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.

To stop the malware/grayware from running when certain files are opened:

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Right-click Start then click Search....
  2. In the Named input box, type the name of the file that was detected earlier.
  3. In the Look In drop-down list, select My Computer then press Enter.
  4. Once located, select the file then press SHIFT+DELETE to delete it.

For Windows Vista and Windows 7:

  1. Click Start>Computer.
  2. In the Search Computer input box, type the name of the file detected earlier, and press Enter.
  3. Once located, select the file then press SHIFT+DELETE to delete it.
    *Note: Read the following Microsoft page if these steps do not work on Windows 7.

Step 7

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