TROJ_STEGVOB.HJ
TrojanDownloader:Win32/Stegvob.B (Microsoft); Generic Downloader.x!ggd (McAfee); Trojan.Zbot (Symantec); PAK:UPX, Trojan-Dropper.Win32.Dapato.teq (Kaspersky); Trojan.Win32.EncPk.gen.abz (v) (Sunbelt); Trojan.Generic.7062476 (FSecure)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan 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 itself after execution.
TECHNICAL DETAILS
44,032 bytes
EXE
Yes
10 Apr 2012
Arrival Details
This Trojan 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 Trojan creates the following folders:
- %User Profile%\Application Data\Keyk
- %User Profile%\Application Data\Eqme
(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 Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{58C4EBA0-47A8-AD40-8C85-A85A94978B48} = "%User Profile%\Keyk\odwu.exe"
Other System Modifications
This Trojan deletes the following files:
- {malware path and file name}.bat
It adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Poryga
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and file name} = "{malware path and file name}:*:enabled:ldrsoft"
HKEY_CURRENT_USER\Software\Microsoft\
Poryga
ai87d48 = "STEwrY/qxIB4h/pO0lozhbDKPdWNwboz??"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
CleanCookies = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Poryga
f9ic252 = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
Poryga
f9ic252 = "ad513135"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
24289:UDP = "24289:UDP:*:Enabled:UDP 24289"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
20353:TCP = "20353:TCP:*:Enabled:TCP 20353"
HKEY_CURRENT_USER\Software\Microsoft\
Poryga
1hbb37ea = "xW9RrWClvYAVh5VO_CHAR(0x03)__CHAR(0x05)_!_CHAR(0x08)_?"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Account Manager
Server ID = "4"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
FirstRun = "1"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkContactRefresh = "0"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkFolderRefresh = "0"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\0
1609 = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
1406 = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
1609 = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\2
1609 = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1406 = "0"
(Note: The default value data of the said registry entry is 3.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1609 = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
1406 = "0"
(Note: The default value data of the said registry entry is 3.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
1609 = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Identities
Last Username = "Main Identity"
(Note: The default value data of the said registry entry is Main Identity.)
HKEY_CURRENT_USER\Identities
Last User ID = "{341F68BA-C841-4200-A7B4-3D5CFF202166}"
(Note: The default value data of the said registry entry is {C0FE0177-5693-4537-9331-A7402AD82D40}.)
HKEY_CURRENT_USER\Identities
Identity Login = "9853"
(Note: The default value data of the said registry entry is 98053.)
HKEY_CURRENT_USER\Identities
Identity Ordinal = "2"
(Note: The default value data of the said registry entry is 1.)
Dropping Routine
This Trojan drops the following files:
- %User Profile%\Application Data\3565592.exe
- %User Profile%\Application Data\4757368.exe
- {malware path and file name}00.bat
- %User Profile%\Keyk\odwu.exe
- %User Profile%\Eqme\lyvyc.ukd
(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 Trojan connects to the following possibly malicious URL:
- http://{BLOCKED}orld.org/melt.exe
It deletes itself after execution.
This report is generated via an automated analysis system.
SOLUTION
9.200
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\Microsoft
- Poryga
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer
- Privacy
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\Run
- {58C4EBA0-47A8-AD40-8C85-A85A94978B48} = "%User Profile%\Keyk\odwu.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- {malware path and file name} = "{malware path and file name}:*:enabled:ldrsoft"
- In HKEY_CURRENT_USER\Software\Microsoft\Poryga
- ai87d48 = "STEwrY/qxIB4h/pO0lozhbDKPdWNwboz??"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Privacy
- CleanCookies = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Poryga
- f9ic252 = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Poryga
- f9ic252 = "ad513135"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- DisableNotifications = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- 24289:UDP = "24289:UDP:*:Enabled:UDP 24289"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- DisableNotifications = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- 20353:TCP = "20353:TCP:*:Enabled:TCP 20353"
- In HKEY_CURRENT_USER\Software\Microsoft\Poryga
- 1hbb37ea = "xW9RrWClvYAVh5VO_CHAR(0x03)__CHAR(0x05)_!_CHAR(0x08)_?"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Account Manager
- Server ID = "4"
- In HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4
- FirstRun = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4
- OlkContactRefresh = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4
- OlkFolderRefresh = "0"
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\Internet Settings\Zones\0
- From: 1609 = "0"
To: 1609 = ""1""
- From: 1609 = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
- From: 1406 = "0"
To: 1406 = ""1""
- From: 1406 = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
- From: 1609 = "0"
To: 1609 = ""1""
- From: 1609 = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
- From: 1609 = "0"
To: 1609 = ""1""
- From: 1609 = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
- From: 1406 = "0"
To: 1406 = ""3""
- From: 1406 = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
- From: 1609 = "0"
To: 1609 = ""1""
- From: 1609 = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
- From: 1406 = "0"
To: 1406 = ""3""
- From: 1406 = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
- From: 1609 = "0"
To: 1609 = ""1""
- From: 1609 = "0"
- In HKEY_CURRENT_USER\Identities
- From: Last Username = "Main Identity"
To: Last Username = ""Main Identity""
- From: Last Username = "Main Identity"
- In HKEY_CURRENT_USER\Identities
- From: Last User ID = "{341F68BA-C841-4200-A7B4-3D5CFF202166}"
To: Last User ID = ""{C0FE0177-5693-4537-9331-A7402AD82D40}""
- From: Last User ID = "{341F68BA-C841-4200-A7B4-3D5CFF202166}"
- In HKEY_CURRENT_USER\Identities
- From: Identity Login = "9853"
To: Identity Login = ""98053""
- From: Identity Login = "9853"
- In HKEY_CURRENT_USER\Identities
- From: Identity Ordinal = "2"
To: Identity Ordinal = ""1""
- From: Identity Ordinal = "2"
Step 6
Search and delete these components
- %User Profile%\Application Data\3565592.exe
- %User Profile%\Application Data\4757368.exe
- {malware path and file name}00.bat
- %User Profile%\Keyk\odwu.exe
- %User Profile%\Eqme\lyvyc.ukd
Step 7
Search and delete these folders
- %User Profile%\Application Data\Keyk
- %User Profile%\Application Data\Eqme
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_STEGVOB.HJ. 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 9
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}.bat
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