WORM_DOWNAD.HG
Worm:Win32/Conficker.B (Microsoft), W32.Downadup.B (Symantec), W32/Conficker.worm.gen.a (McAfee), Win32/Conficker.AC worm (ESET), Worm:W32/Downadup.BW (FSecure), Worm/Conficker.Z.14 (Antivir), Win32.Worm.Downadup.Gen (Bitdefender), Worm.Downadup-41 (ClamAV), W32/Conficker.A!worm (Fortinet), Worm.Win32.Conficker (Ikarus), W32/Conficker.C.worm (Panda),
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: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm may be dropped by other malware.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
TECHNICAL DETAILS
169,043 bytes
DLL
Yes
02 Jan 2014
Arrival Details
This worm may be dropped by other malware.
Other System Modifications
This worm adds the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\zrsfdtme
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_ZRSFDTME
It adds the following registry entries as part of its installation routine:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\zrsfdtme
ImagePath = "%System%\{number}.tmp"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
SuperHidden = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL
CheckedValue = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\BITS
Start = "4"
(Note: The default value data of the said registry entry is 3.)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ERSvc
Start = "4"
(Note: The default value data of the said registry entry is 2.)
HKEY_CURRENT_CONFIG\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyEnable = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Hardware Profiles\0001\Software\
Microsoft\windows\CurrentVersion\
Internet Settings
ProxyEnable = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wscsvc
Start = "4"
(Note: The default value data of the said registry entry is 2.)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wuauserv
Start = "4"
(Note: The default value data of the said registry entry is 2.)
It creates the following registry entry(ies) to bypass Windows Firewall:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
{random port number}:TCP = "{random port number}:TCP:*:Enabled:mdqkva"
Propagation
This worm creates the following folders in all removable drives:
- {removable drive}:\RECYCLER
- {removable drive}:\RECYCLER\S-5-3-42-2819952290-8240758988-879315005-3665
It drops the following copy(ies) of itself in all removable drives:
- {removable drive}:\RECYCLER\S-5-3-42-2819952290-8240758988-879315005-3665\jwgkvsq.vmx
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
The said .INF file contains the following strings:
;{garbage characters}
[AUTorUN
;{garbage characters}
AcTION=Open folder to view files
;{garbage characters}
icon=%syStEmrOot%\sySTEM32\sHELL32.Dll ,4
;{garbage characters}
shelLExECUte=RuNdLl32.EXE .\RECYCLER\S-5-3-42-2819952290-8240758988-879315005-3665\jwgkvsq.vmx,ahaezedrn
;{garbage characters}
Other Details
This worm connects to the following URL(s) to get the affected system's IP address:
- http://www.whatismyip.org/
- http://checkip.dyndns.org/
- http://whatsmyipaddress.com
It connects to the following possibly malicious URL:
- http://{pseudorandom domain}.cc
- http://{pseudorandom domain}.cn
- http://{pseudorandom domain}.ws
- http://{pseudorandom domain}.com
- http://{pseudorandom domain}.net
- http://{pseudorandom domain}.org
- http://{pseudorandom domain}.info
- http://{pseudorandom domain}.biz
NOTES:
Upon execution, it opens a window which displays the files under the malware path's root drive to hide its malicious routines from the user. It modifies its file attributes to Read-only and Hidden after execution.
SOLUTION
9.700
10.516.02
02 Jan 2014
10.517.00
03 Jan 2014
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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
- zrsfdtme
- zrsfdtme
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root
- LEGACY_ZRSFDTME
- LEGACY_ZRSFDTME
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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- {random port number}:TCP = "{random port number}:TCP:*:Enabled:mdqkva"
- {random port number}:TCP = "{random port number}:TCP:*:Enabled:mdqkva"
Step 5
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 HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: Hidden = "2"
To: Hidden = "1"
- From: Hidden = "2"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: SuperHidden = "0"
To: SuperHidden = "1"
- From: SuperHidden = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
- From: CheckedValue = "0"
To: CheckedValue = "1"
- From: CheckedValue = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BITS
- From: Start = "4"
To: Start = "3"
- From: Start = "4"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ERSvc
- From: Start = "4"
To: Start = "2"
- From: Start = "4"
- In HKEY_CURRENT_CONFIG\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- From: ProxyEnable = "0"
To: ProxyEnable = "1"
- From: ProxyEnable = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Hardware Profiles\0001\Software\Microsoft\windows\CurrentVersion\Internet Settings
- From: ProxyEnable = "0"
To: ProxyEnable = "1"
- From: ProxyEnable = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\wscsvc
- From: Start = "4"
To: Start = "2"
- From: Start = "4"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\wuauserv
- From: Start = "4"
To: Start = "2"
- From: Start = "4"
Step 6
Search and delete AUTORUN.INF files created by WORM_DOWNAD.HG that contain these strings
[AUTorUN
;{garbage characters}
AcTION=Open folder to view files
;{garbage characters}
icon=%syStEmrOot%\sySTEM32\sHELL32.Dll ,4
;{garbage characters}
shelLExECUte=RuNdLl32.EXE .\RECYCLER\S-5-3-42-2819952290-8240758988-879315005-3665\jwgkvsq.vmx,ahaezedrn
;{garbage characters}
Step 7
Search and delete these folders
- {removable drive}:\RECYCLER
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_DOWNAD.HG. 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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