BKDR_DARKCOMET.AS
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
TECHNICAL DETAILS
372,224 bytes
EXE
Yes
29 Apr 2014
Arrival Details
This backdoor 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 backdoor drops the following copies of itself into the affected system:
- %User Profile%\Microsoft FxCop\SamSs.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 creates the following folders:
- %User Profile%\Application Data\Microsoft FxCop
- %User Profile%\Application Data\dclogs
(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.)
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
WMI Performance Adapter = "%User Profile%\Microsoft FxCop\wmiApSrv.exe"
Other System Modifications
This backdoor deletes the following files:
- {malware path and file name}:zone.identifier
- %User Profile%\Microsoft FxCop\wmiApSrv.exe:Zone.Identifier
- %User Profile%\Microsoft FxCop\SamSs.exe:Zone.Identifier
- %User Profile%\Microsoft FxCop\SamSs.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 adds the following registry keys:
HKEY_CURRENT_USER\Software\DC3_FEXEC
It adds the following registry entries:
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:00:27 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:00:32 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:00:35 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:00:38 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:00:42 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:00:45 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:00:48 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:00:52 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:00:55 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:00:58 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:02 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:05 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:08 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:11 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:15 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:18 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:21 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:25 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:28 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:31 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:35 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:38 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:42 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:45 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:48 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:52 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:55 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:01:58 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:02:02 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:02:05 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:02:08 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:02:12 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:02:15 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:02:18 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:02:22 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:02:25 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:02:29 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:02:32 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:02:35 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
HKEY_CURRENT_USER\Software\DC3_FEXEC
4/25/2014 at 11:02:39 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
Dropping Routine
This backdoor drops the following files:
- %User Profile%\Microsoft FxCop\wmiApSrv.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.)
Other Details
This backdoor connects to the following possibly malicious URL:
- {BLOCKED}.34.210
This report is generated via an automated analysis system.
SOLUTION
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
Restart in Safe Mode
Step 3
Delete this registry key
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
- DC3_FEXEC
Step 4
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\RunOnce
- WMI Performance Adapter = "%User Profile%\Microsoft FxCop\wmiApSrv.exe"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:00:27 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:00:32 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:00:35 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:00:38 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:00:42 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:00:45 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:00:48 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:00:52 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:00:55 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:00:58 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:02 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:05 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:08 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:11 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:15 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:18 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:21 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:25 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:28 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:31 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:35 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:38 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:42 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:45 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:48 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:52 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:55 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:01:58 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:02:02 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:02:05 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:02:08 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:02:12 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:02:15 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:02:18 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:02:22 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:02:25 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:02:29 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:02:32 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:02:35 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 4/25/2014 at 11:02:39 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
Step 5
Search and delete this file
- %User Profile%\Microsoft FxCop\wmiApSrv.exe
Step 6
Search and delete these folders
- %User Profile%\Application Data\Microsoft FxCop
- %User Profile%\Application Data\dclogs
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_DARKCOMET.AS. 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 8
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- {malware path and file name}:zone.identifier
- %User Profile%\Microsoft FxCop\wmiApSrv.exe:Zone.Identifier
- %User Profile%\Microsoft FxCop\SamSs.exe:Zone.Identifier
- %User Profile%\Microsoft FxCop\SamSs.exe
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