arrow_back
search
close

BKDR_CYCBOT.SMIB

October 08, 2013
 Analysis by: Cris Nowell Pantanilla
 ALIASES:

Backdoor:Win32/Cycbot.B [Microsoft], Backdoor.Cycbot!gen3 [Symantec]

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This malware acts as a proxy server to intercept requests of Internet browsers and point them to the proxy server on port 64323.

It monitors Internet browser's activity to check for certain strings related to popular websites such as search engines and social networking sites to intercept information.

It monitors the address bar of Web browsers and redirects to other pages if the address contains certain strings.

This backdoor may be downloaded by other malware/grayware/spyware from remote sites. It may be dropped by other malware. It may be unknowingly downloaded by a user while visiting malicious websites.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

18 May 2011

Payload:

Monitors Internet browser's activity, Connects to URLs/IPs, Drops files, Terminates processes

Arrival Details

This backdoor may be downloaded by other malware/grayware/spyware from remote sites.

It may be dropped by other malware.

It may be unknowingly downloaded by a user while visiting malicious websites.

Installation

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

  • %User Temp%\csrss.exe

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

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

  • {A5B35993-9674-43cd-8AC7-5BC5013E617B}
  • {35BCA615-C82A-4152-8857-BCC626AE4C8D}
  • {C0429A47-0CF0-4d1b-9616-C588FA0A3DDB}
  • {43B671F0-5D50-4dbe-AD9C-64A6167C57AD}
  • {6B985724-623F-492e-B0D6-C9715ADE853B}
  • {B37C48AF-B05C-4520-8B38-2FE181D5DC78}
  • {95F6585C-CC1E-4b52-A63B-9FBC6A94F371}

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = explorer.exe,%Application Data%\dwm.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
conhost = %Application Data%\Microsoft\conhost.exe

Other System Modifications

This backdoor adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyServer = http=127.0.0.1:64323

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Hardware Profiles\0001\Software\
Microsoft\windows\CurrentVersion\
Internet Settings
ProxyEnable = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Hardware Profiles\Current\Software\
Microsoft\windows\CurrentVersion\
Internet Settings
ProxyEnable = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_CURRENT_CONFIG\Software\Microsoft\
windows\CurrentVersion\Internet Settings
ProxyEnable = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows Defender
DisableAntiSpyware = "1"

(Note: The default value data of the said registry entry is 0.)

Backdoor Routine

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

  • http://{BLOCKED}linecatalog.com
  • http://{BLOCKED}pmusiconline.com
  • http://{BLOCKED}temilkandtee.com
  • http://{BLOCKED}eeddbsearch.com
  • http://{BLOCKED}gsourcecodes.com
  • http://{BLOCKED}gamesonlines.com
  • http://{BLOCKED}backuostore4you.com
  • http://{BLOCKED}eyescat.com
  • http://{BLOCKED}skopia.com
  • http://{BLOCKED}oisdb.com
  • http://{BLOCKED}grammingshool.com
  • http://{BLOCKED}cureonline.com
  • http://{BLOCKED}aclubonline.com
  • http://{BLOCKED}ioz.com

Process Termination

This backdoor terminates processes or services that contain any of the following strings if found running in the affected system's memory:

  • avgnt.exe
  • Avira*
  • ccsvchst.exe
  • Norton*
  • Symantec*
  • AvastUI.exe
  • Alwil Software*
  • Avast*
  • mcagent.exe
  • McAfee*
  • avira
  • norton
  • avast
  • mcafee
  • bitdef
  • kasper
  • drweb
  • nod32

Dropping Routine

This backdoor drops the following files wherein it saves the information it gathers:

  • %Application Data%\9EAE.6BA

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

Download Routine

This backdoor connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}rom.at/polytheism/pictures/TanzenderShiva.jpg
  • http://{BLOCKED}eafdesign.com/blog/images/share/stumble.png
  • http://{BLOCKED}eafdesign.com/blog/images/share/facebook.png
  • http://{BLOCKED}twaredevelopment.com/WindowsLiveWriter/web-2_0_thumb_1.gif
  • http://{BLOCKED}tar.com/avatar.php?gravatar_id=f2a3889aff6fc9711a3cbcfe64067be1
  • http://{BLOCKED}tar.com/avatar.php?gravatar_id=f2a3889aff6fc9711a3cbcfe64067be2
  • http://{BLOCKED}ho.com/wp-content/uploads/2010/09/web-20-what-is-300x251.jpg
  • http://{BLOCKED}fk.com/img/icons/twitter.png
  • http://{BLOCKED}fk.com/img/icons/facebook.png
  • http://{BLOCKED}ylifenow.com/templates/7348/images/header_logo.jpg
  • http://{BLOCKED}ylifenow.com/templates/7349/images/header_logo.jpg
  • http://{BLOCKED}ndandbarrett.com/images/footer/account.jpg
  • http://{BLOCKED}dandbarrett.com/images/footer/account.gif
  • http://{BLOCKED}sautoelectric.com/images/50-217-1_F_1_.jpg
  • http://{BLOCKED}autoelectric.com/images/50-217-1_F_2_.jpg
  • http://{BLOCKED}zdirectory.com/images/PowerShowBanner.gif
  • http://{BLOCKED}zdirectory.com/images/PowerHideBanner.gif
  • http://{BLOCKED}paganda.net/blog/pics/3321.jpg
  • http://{BLOCKED}paganda.net/blog/pics/3322.jpg
  • http://{BLOCKED}segreenteaonline.com/assets/images/greentea-cha-1.gif
  • http://{BLOCKED}segreenteaonline.com/assets/images/greentea-cha-2.gif
  • http://{BLOCKED}rbalteaonline.com/images/greenherbalteagirlholdingcup250.gif
  • http://{BLOCKED}erbalteaonline.com/images/greenherbalteagirlholdingcup350.gif
  • http://{BLOCKED}institute.com/g7/images/logo.jpg
  • http://{BLOCKED}institute.com/g7/images/logo2.jpg
  • http://{BLOCKED}institute.com/g7/images/logo3.jpg
  • http://{BLOCKED}institute.com/g7/images/logo4.jpg
  • http://{BLOCKED}datingsecretfriends.com/images/im133.jpg
  • http://{BLOCKED}edatingsecretfriends.com/images/im134.jpg
  • http://{BLOCKED}ats.com/images/logo.png

It saves the files it downloads using the following names:

  • %Application Data%\Microsoft\conhost.exe
  • %Application Data%\dwm.exe
  • %User Temp%\2.exe

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

Trend Micro detects the dowloaded file as:

  • BKDR_CYCBOT.SMIB

NOTES:

This malware acts as a proxy server to intercept requests of Internet browsers and point them to the proxy server on port 64323.

It monitors Internet browser's activity to check for the following strings related to popular websites such as search engines and social networking sites to intercept information:

  • .2mdn.
  • .abmr.
  • .adtechus.
  • .aol.
  • .atdmt.
  • .atwola.
  • .autodatadirect.
  • .bing.net
  • .dartsearch.
  • .doubleclick.
  • .ggpht.
  • .google
  • .ivwbox.
  • .mapquestapi.
  • .microsoft.
  • .opera.
  • .tacoda.
  • .thawte.
  • .tlowdb.
  • .truveo.
  • .virtualearth.
  • .wsod.
  • .yimg.com
  • .ypcdn.
  • amazon.
  • aol/search
  • aolcdn.
  • aolsvc.
  • bing.com
  • bing.com/search
  • blogger
  • brightcove.com
  • doubleclick.
  • ebay.
  • facebook.
  • flickr
  • google-analytics.
  • google.
  • googlesyndication.
  • googleusercontent.
  • gstatic.
  • imdb.
  • mapq.st
  • scorecardresearch.com
  • search.aol.
  • search.yahoo.com/search
  • searcht2.aol.
  • suche.aol.
  • twitter.
  • wikimedia.
  • wikipedia.
  • yahoo.
  • yahoo.com
  • youtube.
  • ytimg.
  • /complete/search
  • /gen_204
  • /images
  • /imglanding
  • ?query=
  • &query=

It monitors the address bar of Web browsers and redirects to other pages if the address contains any of the following strings:

  • Avast
  • Avira
  • Dr.Web
  • Kaspersky
  • McAfee
  • ESET NOD32
  • Norton
  • BitDefender

  SOLUTION

Minimum Scan Engine:

8.900

FIRST VSAPI PATTERN FILE:

8.162.09

FIRST VSAPI PATTERN DATE:

18 May 2011

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

Identify and terminate files detected as BKDR_CYCBOT.SMIB

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

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 KEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
    • Shell = explorer.exe,%Application Data%\dwm.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • conhost = %Application Data%\Microsoft\conhost.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
    • ProxyServer = http=127.0.0.1:55495

Step 4

Restore this modified 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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Hardware Profiles\0001\Software\Microsoft\windows\CurrentVersion\Internet Settings
    • From: ProxyEnable = 1
      To: ProxyEnable = 0
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Hardware Profiles\Current\Software\Microsoft\windows\CurrentVersion\Internet Settings
    • From: ProxyEnable = 1
      To: ProxyEnable = 0
  • In HKEY_CURRENT_CONFIG\Software\Microsoft\windows\CurrentVersion\Internet Settings
    • From: ProxyEnable = 1
      To: ProxyEnable = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender
    • From: DisableAntiSpyware = 1
      To: DisableAntiSpyware = 0

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.
  • %Application Data%\9EAE.6BA

Step 6

Scan your computer with your Trend Micro product to delete files detected as BKDR_CYCBOT.SMIB. 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.


Did this description help? Tell us how we did.