TROJ_AGENT_039771.TOMB
PWS:Win32/Zbot (Microsoft); PWS-Zbot.gen.aae (McAfee); Trojan.Zbot (Symantec); Trojan.Win32.Generic!BT (Sunbelt); Gen:Variant.Zusy.7999 (FSecure)
Windows 2000, Windows XP, Windows Server 2003
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
272,384 bytes
EXE
Yes
30 Jul 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\Upurih
- %User Profile%\Application Data\Ykba
- %User Profile%\Application Data\Kofo
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
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
Okyhze = "%User Profile%\Upurih\ewubw.exe"
Other System Modifications
This Trojan adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Orwi
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
CleanCookies = "0"
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"
HKEY_CURRENT_USER\Software\Microsoft\
Orwi
Wyrinaga = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Account Manager\Accounts
ConnectionSettingsMigrated = "1"
HKEY_CURRENT_USER\Identities\{341F68BA-C841-4200-A7B4-3D5CFF202166}\
Software\Microsoft\Outlook Express\
5.0
StoreMigratedV5 = "1"
HKEY_CURRENT_USER\Identities\{341F68BA-C841-4200-A7B4-3D5CFF202166}\
Software\Microsoft\Outlook Express\
5.0
Settings Upgraded = "7"
HKEY_CURRENT_USER\Identities\{341F68BA-C841-4200-A7B4-3D5CFF202166}\
Software\Microsoft\Outlook Express\
5.0
Running = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Account Manager\Accounts
AssociatedID = "{random values}"
HKEY_CURRENT_USER\Identities\{341F68BA-C841-4200-A7B4-3D5CFF202166}\
Software\Microsoft\Outlook Express\
5.0
Running = "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%\Upurih\ewubw.exe
- %User Profile%\Ykba\meibz.uro
- %User Profile%\Kofo\piva.wiy
- %Application Data%\Identities\{341F68BA-C841-4200-A7B4-3D5CFF202166}\Microsoft\Outlook Express\Sent Items.dbx
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)
Other Details
This Trojan connects to the following possibly malicious URL:
- http://{BLOCKED}optoday.ru/translate/file.php
It deletes itself after execution.
This report is generated via an automated analysis system.
SOLUTION
9.200
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
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
- Orwi
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer
- Privacy
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion
- Uninstall
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
- Okyhze = "%User Profile%\Upurih\ewubw.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Privacy
- CleanCookies = "0"
- 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"
- In HKEY_CURRENT_USER\Software\Microsoft\Orwi
- Wyrinaga = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Account Manager\Accounts
- ConnectionSettingsMigrated = "1"
- In HKEY_CURRENT_USER\Identities\{341F68BA-C841-4200-A7B4-3D5CFF202166}\Software\Microsoft\Outlook Express\5.0
- StoreMigratedV5 = "1"
- In HKEY_CURRENT_USER\Identities\{341F68BA-C841-4200-A7B4-3D5CFF202166}\Software\Microsoft\Outlook Express\5.0
- Settings Upgraded = "7"
- In HKEY_CURRENT_USER\Identities\{341F68BA-C841-4200-A7B4-3D5CFF202166}\Software\Microsoft\Outlook Express\5.0
- Running = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Account Manager\Accounts
- AssociatedID = "{random values}"
- In HKEY_CURRENT_USER\Identities\{341F68BA-C841-4200-A7B4-3D5CFF202166}\Software\Microsoft\Outlook Express\5.0
- Running = "0"
Step 5
Restore this modified 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\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 files
- %User Profile%\Upurih\ewubw.exe
- %User Profile%\Ykba\meibz.uro
- %User Profile%\Kofo\piva.wiy
- %Application Data%\Identities\{341F68BA-C841-4200-A7B4-3D5CFF202166}\Microsoft\Outlook Express\Sent Items.dbx
Step 7
Search and delete these folders
- %User Profile%\Application Data\Upurih
- %User Profile%\Application Data\Ykba
- %User Profile%\Application Data\Kofo
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_AGENT_039771.TOMB. 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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