BKDR_CYCBOT.TX
Microsoft : Backdoor:Win32/Cycbot.B; Symantec : Backdoor.Cycbot!gen2
Windows 2000, XP, Server 2003
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This backdoor may be dropped by other malware. It may be unknowingly downloaded by a user while visiting malicious websites.
TECHNICAL DETAILS
Varies
PE
Yes
12 Dec 2010
Connects to URLs/Ips, Steals information, Downloads files
Arrival Details
This backdoor may be dropped by other malware.
It may be unknowingly downloaded by a user while visiting malicious websites.
Installation
This backdoor drops the following non-malicious file:
- %Application Data%\A1B2.580
(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.)
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
It modifies the following registry entry(ies) to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
load = %User Temp%\csrss.exe
Other System Modifications
This backdoor adds the following registry entries as part of its installation routine:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyServer = http=127.0.0.1:{random port}
It modifies the following registry entries:
HKEY_CURRENT_USER\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\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.)
Dropping Routine
This backdoor drops the following file(s), into which it saves gathered information:
- %Application Data%\Microsoft\stor.cfg
(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.)
Stolen Information
This backdoor sends the gathered information via HTTP POST to the following URL:
- http://{BLOCKED}fic.cn/pics/23.jpg
Other Details
This backdoor does the following:
- Acts as a proxy server to intercept requests of the following internet browsers and point them to the proxy server on a random port that it sets in the registry:
- Internet Explorer
- Mozilla Firefox
- Opera
- Monitors user's Internet browsing activity and check for the following strings of popular websites such as search engines and social networking sites to steal information:
- &query=
- .2mdn.
- .abmr.
- .adtechus.
- .aol.
- .atdmt.
- .atwola.
- .autodatadirect.
- .bing.net
- .dartsearch.
- .doubleclick.
- .ggpht.
- .ivwbox.
- .mapquestapi.
- .microsoft.
- .opera.
- .tacoda.
- .thawte.
- .tlowdb.
- .truveo.
- .virtualearth.
- .wsod.
- .yimg.com
- .ypcdn.
- /complete/search
- /gen_204
- /images
- /imglanding
- ?query=
- amazon
- aol/search
- aolcdn.
- aolsvc.
- bing.com
- bing.com/search
- blogger
- brightcove.com
- err069
- flickr
- google.
- http%3A%2F%2F
- mapq.st
- scorecardresearch.com
- search.aol.
- search.yahoo.com/search
- searcht2.aol.
- start=0
- suche.aol.
- wikipedia
- yahoo.
- yahoo.com
- youtube
- Connects to the following URLs to download an updated copy of itself and possibly other malicious files:
- http://{BLOCKED}.com
- http://{BLOCKED}.com
- http://{BLOCKED}mpage.com
- http://{BLOCKED}ompage.com
- http://{BLOCKED}mywebconnection.com
- http://{BLOCKED}archive.com
- http://{BLOCKED}driversonline.com
- http://{BLOCKED}wcounter.com
- http://{BLOCKED}emonitoring.com
- http://{BLOCKED}sstore.com
- images/im133.jpg?tq={parameter}
- images/im134.jpg?tq={parameter}
- images/im135.jpg?tq={parameter}
- http://freeonlinedatingtips.net/images/dating1.jpg
- http://sharewareconnection.com/images/ubar_0.jpg
- http://sharewareconnection.com/images/ubar_1.jpg
- http://sharewareconnection.com/im/s.cgi
- http://www.internetsecure.com/images/ismerch.gif
- http://136136.com/lb5000/non-cgi/images/leoca.gif
- http://136136.com/LB5000/CGI-BIN/topic.cgi
- http://136136.com/LB5000/CGI-BIN/s.cgi
- http://pcdocpro.com/images/logo-1.jpg
- http://pcdocpro.com/images/logo-2.jpg
- http://historykillerpro.com/img/eslogo.gif
- http://blenderartists.org/external/Banners/facebook.jpg
- http://blenderartists.org/external/Banners/facebook2.jpg
- Saves the files it downloads which may be an updated copy of itself or other malicious files, using the following names:
- %User Temp%\csrss.exe
- %Application Data%\dwm.exe
- %Application Data%\Microsoft\conhost.exe
SOLUTION
8.900
7.696.01
12 Dec 2010
12/12/2010 12:00:00 AM
7.697.00
12 Dec 2010
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.TX
- 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.
- 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.
- 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
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\Internet Settings
- ProxyServer = http=127.0.0.1:55636
- ProxyServer = http=127.0.0.1:55636
- In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
- Shell = explorer.exe,C:\Documents and Settings\winxp.BATCH57.000\Application Data\dwm.exe
- Shell = explorer.exe,C:\Documents and Settings\winxp.BATCH57.000\Application Data\dwm.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- conhost = C:\Documents and Settings\winxp.BATCH57.000\Application Data\Microsoft\conhost.exe
- conhost = C:\Documents and Settings\winxp.BATCH57.000\Application Data\Microsoft\conhost.exe
Step 4
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In
To: ws\CurrentVersion\Internet Settings- From: ProxyEnable = 1
To: ProxyEnable = 0
- From: ProxyEnable = 1
- In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
- From: load = C:\DOCUME~1\WINXPB~1.000\LOCALS~1\Temp\csrss.exe
To: load = {null}
- From: load = C:\DOCUME~1\WINXPB~1.000\LOCALS~1\Temp\csrss.exe
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Hardware Profiles\0001\Software\Microsoft\windows\CurrentVersion\Internet Settings
- From: ProxyEnable = 1
To: ProxyEnable = 0
- From: ProxyEnable = 1
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Hardware Profiles\Current\Software\Microsoft\windows\CurrentVersion\Internet Settings
- From: ProxyEnable = 1
To: ProxyEnable = 0
- From: ProxyEnable = 1
- In HKEY_CURRENT_CONFIG\Software\Microsoft\windows\CurrentVersion\Internet Settings
- From: ProxyEnable = 1
To: ProxyEnable = 0- From:
- From:
- From: ProxyEnable = 1
Step 5
Search and delete these components
Step 6
Scan your computer with your Trend Micro product to delete files detected as BKDR_CYCBOT.TX. 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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