BKDR_ANDROM.JN
Troj/VB-GQT(Sophos lite), Trojan horse VB2.YHI(AVG), W32/Kryptik.BJGB!tr(Fortinet), W32/Gamarue.E (exact)(Fprot), Trojan.Gamarue(Ikarus), Trojan-Spy.Win32.Zbot.ntnl(Kaspersky), Worm:Win32/Gamarue.AC(Microsoft), Win32/TrojanDownloader.Wauchos.K trojan(NOD32), Trojan.GenericKD.1135767(BitDefender)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
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.
It deletes the initially executed copy of itself.
TECHNICAL DETAILS
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:
- %All Users Profile%\{random file name}.exe
- %All Users Profile%\svchost.exe - for operating systems running on virtual machine
- %ProgramData%\{random file name}.exe - added copy for Windows Vista and above
- %ProgramData%\svchost.exe - added copy for Windows Vista and above running on virtual machine
(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This is usually C:\ProgramData in Windows Vista and 7, or C:\Program Files on Windows 2000, XP (32-bit), and Server 2003, or C:\Program Files (x86) on Windows XP (64-bit).)
It injects codes into the following process(es):
- %System%\svchost.exe
- %System%\msiexec.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
{random number} = "%ProgramData%\{random file name}.exe" (For Windows Vista and above)
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
{random number} = "%All Users Profile%\{random file name}.exe"
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
SunJavaUpdateSched = "%ProgramData%\svchost.exe" (For Windows Vista and above running on Virtual Machine)
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
SunJavaUpdateSched = "%All Users Profile%\svchost.exe" (For versions lower than Windows Vista running on Virtual Machine)
It modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\run
SunJavaUpdateSched = "%All Users Profile%\svchost.exe"
(Note: The default value data of the said registry entry is "%Java Update Folder%\jusched.exe".)
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\run
SunJavaUpdateSched = "%ProgramData%\svchost.exe" (For Windows Vista and above running on Virtual Machine)
(Note: The default value data of the said registry entry is "%Java Update Folder%\jusched.exe".)
Other System Modifications
This backdoor adds the following registry keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\policies\
Explorer
Run =
It creates the following registry entry(ies) to bypass Windows Firewall:
HKEY_LOCAL_MACHINE\System\CurrentControlSe\
Services\SharedAcces\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%System%\msiexec.exe = "%System%\msiexec.exe:*:Generic Host Process"
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%System%\svchost.exe = "%System%\svchost.exe:*:Generic Host Process"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and file name} = "{malware path and file name}:*:Enabled:Compd bibionid perfecti"
Backdoor Routine
This backdoor connects to the following URL(s) to send and receive commands from a remote malicious user:
- http://{BLOCKED}a.ru/beijing.php
- http://{BLOCKED}s.pl/qingdao.php
- http://{BLOCKED}i.ru/warradale.php
- http://{BLOCKED}x.pl/villahermosa.php
- http://www.{BLOCKED}ov.net/goto.php?num=146897
As of this writing, the said sites are inaccessible.
Other Details
This backdoor connects to the following URL(s) to check for an Internet connection:
- update.microsoft.com
It deletes the initially executed copy of itself
NOTES:
When running in a Virtual Machine, this malwares opens Port:8000, which could be used for remote command execution.
It checks internet connection and tries to connect to the following sites every 5 minutes:
- {BLOCKED}a.ru
- {BLOCKED}s.pl
- {BLOCKED}i.ru
- {BLOCKED}x.pl
SOLUTION
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 BKDR_ANDROM.JN
Step 3
Restart in Safe Mode
Step 4
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_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\policies\Explorer
- Run
- Run
Step 5
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_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
- SunJavaUpdateSched = "%ProgramData%\svchost.exe" (For Windows Vista and above running on Virtual Machine)
- SunJavaUpdateSched = "%ProgramData%\svchost.exe" (For Windows Vista and above running on Virtual Machine)
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
- SunJavaUpdateSched = "%All Users Profile%\svchost.exe" (For versions lower than Windows Vista running on Virtual Machine)
- SunJavaUpdateSched = "%All Users Profile%\svchost.exe" (For versions lower than Windows Vista running on Virtual Machine)
- In HKEY_LOCAL_MACHINE\System\CurrentControlSe\Services\SharedAcces\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- %System%\msiexec.exe = "%System%\msiexec.exe:*:Generic Host Process"
- %System%\msiexec.exe = "%System%\msiexec.exe:*:Generic Host Process"
- In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- %System%\svchost.exe = "%System%\svchost.exe:*:Generic Host Process"
- %System%\svchost.exe = "%System%\svchost.exe:*:Generic Host Process"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- {malware path and file name} = "{malware path and file name}:*:Enabled:Compd bibionid perfecti"
- {malware path and file name} = "{malware path and file name}:*:Enabled:Compd bibionid perfecti"
Step 6
Restore this modified registry value
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 HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\run
- From: SunJavaUpdateSched = "%All Users Profile%\svchost.exe"
To: SunJavaUpdateSched = "%Java Update Folder%\jusched.exe"
- From: SunJavaUpdateSched = "%All Users Profile%\svchost.exe"
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\run
- From: SunJavaUpdateSched = "%ProgramData%\svchost.exe" (For Windows Vista and above running on Virtual Machine)
To: SunJavaUpdateSched = "%Java Update Folder%\jusched.exe"
- From: SunJavaUpdateSched = "%ProgramData%\svchost.exe" (For Windows Vista and above running on Virtual Machine)
Step 7
Search and delete these files
- %All Users Profile%\{random file name}.exe
- %All Users Profile%\svchost.exe - For Operating Systems running on Virtual Machine.
- %ProgramData%\{random file name}.exe - Added copy for Windows Vista and above.
- %ProgramData%\svchost.exe - Added copy for Windows Vista and above running on Virtual Machine.
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_ANDROM.JN. 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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