ALIASES:

PWS:Win32/Zbot.gen!AF (Microsoft); PWS-Zbot.gen.xt (McAfee); Packed.Generic.362 (Symantec); Packed.Win32.Krap.iu (Kaspersky); Trojan.Win32.Generic!SB.0 (Sunbelt); Gen:Variant.Kazy.65708 (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • 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

File Size: 313,896 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 24 Jun 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\Weebd

(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
{58C4EBA0-47A8-AD40-8C85-A85A94978B48} = "%User Profile%\Weebd\izzeuw.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Osih

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Osih
1061ej1g = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
CleanCookies = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Osih
1520h58a = "1vD/Aw==?_CHAR(0x03)_?"

HKEY_CURRENT_USER\Software\Microsoft\
Osih
1520h58a = "1/D/Aw==_CHAR(0x03)__CHAR(0x03)_?_CHAR(0x0C)_?EAS"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
14664:UDP = "14664:UDP:*:Enabled:UDP 14664"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
28107:TCP = "28107:TCP:*:Enabled:TCP 28107"

HKEY_CURRENT_USER\Software\Microsoft\
Osih
31eg605a = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Osih
1d7c332f = "{random characters}"

HKEY_CURRENT_USER\Software\Microsoft\
Osih
e0a38b3 = "{random characters}"

HKEY_CURRENT_USER\Software\Microsoft\
Osih
e0a38b3 = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Osih
1d7c332f = "{random values}"

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\
Osih
1520h58a = "3fff97"

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\Weebd
  • %User Profile%\Weebd\izzeuw.exe
  • %Application Data%\isicaw.ezp

(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 deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 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

[ Learn More ]

Step 3

Delete this registry key

[ Learn More ]

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
    • Osih
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer
    • Privacy

Step 4

Delete this registry value

[ Learn More ]

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%\Weebd\izzeuw.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Osih
    • 1061ej1g = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Privacy
    • CleanCookies = "0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Osih
    • 1520h58a = "1vD/Aw==?_CHAR(0x03)_?"
  • In HKEY_CURRENT_USER\Software\Microsoft\Osih
    • 1520h58a = "1/D/Aw==_CHAR(0x03)__CHAR(0x03)_?_CHAR(0x0C)_?EAS"
  • 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
    • 14664:UDP = "14664:UDP:*:Enabled:UDP 14664"
  • 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
    • 28107:TCP = "28107:TCP:*:Enabled:TCP 28107"
  • In HKEY_CURRENT_USER\Software\Microsoft\Osih
    • 31eg605a = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Osih
    • 1d7c332f = "{random characters}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Osih
    • e0a38b3 = "{random characters}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Osih
    • e0a38b3 = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Osih
    • 1d7c332f = "{random values}"
  • 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\Osih
    • 1520h58a = "3fff97"

Step 5

Restore this modified registry value

[ Learn More ]

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""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
    • From: 1406 = "0"
      To: 1406 = ""1""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
    • From: 1609 = "0"
      To: 1609 = ""1""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
    • From: 1609 = "0"
      To: 1609 = ""1""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • From: 1406 = "0"
      To: 1406 = ""3""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • From: 1609 = "0"
      To: 1609 = ""1""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
    • From: 1406 = "0"
      To: 1406 = ""3""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
    • From: 1609 = "0"
      To: 1609 = ""1""
  • In HKEY_CURRENT_USER\Identities
    • From: Last Username = "Main Identity"
      To: 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}""
  • In HKEY_CURRENT_USER\Identities
    • From: Identity Login = "9853"
      To: Identity Login = ""98053""
  • In HKEY_CURRENT_USER\Identities
    • From: Identity Ordinal = "2"
      To: Identity Ordinal = ""1""

Step 6

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %User Profile%\Application Data\Weebd
  • %User Profile%\Weebd\izzeuw.exe
  • %Application Data%\isicaw.ezp

Step 7

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %User Profile%\Application Data\Weebd

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_AGENT_009643.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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