BKDR_ANDROM.EDS
Win32/TrojanDownloader.Wauchos.I trojan (NOD32), Troj/Mdrop-EWX (Sophos)
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:
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 executes then deletes itself afterward.
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
It executes then deletes itself afterward.
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\Run
SunJavaUpdateSched = "{All Users' Profile}\svchost.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
{random number} = "{All Users' Profile}\{random file name}.exe"
Other System Modifications
This backdoor adds the following registry keys as part of its installation routine:
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\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
%System%\msiexec.exe = "%System%\msiexec.exe:*:Generic Host Process"
Other Details
This backdoor connects to the following possibly malicious URL:
- http://{BLOCKED}c.pl/support.php
- http://{BLOCKED}o.pl/wp-rss2.php
- http://{BLOCKED}a.ru/soap.php
- http://{BLOCKED}a.ru/blog.php
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.EDS
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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system 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 = "{All Users' Profile}\svchost.exe"
- SunJavaUpdateSched = "{All Users' Profile}\svchost.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\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"
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_ANDROM.EDS. 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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