TSPY_ZBOT.HXL

October 12, 2012
 ALIASES:

PWS:Win32/Zbot.gen!AF (Microsoft); Trojan.Gen (Symantec); PAK:UPX, Trojan-Spy.Win32.Zbot.cyyz (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); ERROR (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This spyware 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 the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

302,592 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

27 Dec 2011

Arrival Details

This spyware 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 spyware creates the following folders:

  • %User Profile%\Application Data\Geyj
  • %User Profile%\Application Data\Igojal

(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 spyware 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%\Geyj\muhyc.exe""

It registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Uzahga

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Uzahga
9f82hc2 = "xKtQ9Q==?_CHAR(0x03)_?"

HKEY_CURRENT_USER\Software\Microsoft\
Uzahga
ed5h3cc = {random values}

HKEY_CURRENT_USER\Software\Microsoft\
Uzahga
9f82hc2 = f55ab8d

HKEY_CURRENT_USER\Software\Microsoft\
Uzahga
9f82hc2 = f55ab8c

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

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
26743:UDP = "26743:UDP:*:Enabled:UDP 26743"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
22997:TCP = "22997:TCP:*:Enabled:TCP 22997"

HKEY_CURRENT_USER\Software\Microsoft\
Uzahga
1i04h4ae = "6sNQ9Y19yfiris+E?_CHAR(0x05)_?"

HKEY_CURRENT_USER\Software\Microsoft\
Uzahga
1aaa81b = {random characters}

HKEY_CURRENT_USER\Software\Microsoft\
Uzahga
1aaa81b = {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\Identities
Last Username = "Main Identity"

HKEY_CURRENT_USER\Identities
Last User ID = "{341F68BA-C841-4200-A7B4-3D5CFF202166}"

HKEY_CURRENT_USER\Identities
Identity Login = 9853

HKEY_CURRENT_USER\Identities
Identity Ordinal = 2

HKEY_CURRENT_USER\Software\Microsoft\
Uzahga
9f82hc2 = "zKtQ9Q==_CHAR(0x07)__CHAR(0x03)_u_CHAR(0x0E)_"

Dropping Routine

This spyware drops the following files:

  • %User Profile%\Geyj\muhyc.exe
  • %User Profile%\Igojal\awceu.mea

(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.)

Other Details

This spyware deletes the initially executed copy of itself

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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts
    • List
  • In HKEY_CURRENT_USER\Software\Microsoft
    • Uzahga
  • 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%\Geyj\muhyc.exe""
  • In HKEY_CURRENT_USER\Software\Microsoft\Uzahga
    • 9f82hc2="xKtQ9Q==?_CHAR(0x03)_?"
  • In HKEY_CURRENT_USER\Software\Microsoft\Uzahga
    • ed5h3cc={random values}
  • In HKEY_CURRENT_USER\Software\Microsoft\Uzahga
    • 9f82hc2=f55ab8d
  • In HKEY_CURRENT_USER\Software\Microsoft\Uzahga
    • 9f82hc2=f55ab8c
  • 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
    • 26743:UDP="26743:UDP:*:Enabled:UDP 26743"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
    • 22997:TCP="22997:TCP:*:Enabled:TCP 22997"
  • In HKEY_CURRENT_USER\Software\Microsoft\Uzahga
    • 1i04h4ae="6sNQ9Y19yfiris+E?_CHAR(0x05)_?"
  • In HKEY_CURRENT_USER\Software\Microsoft\Uzahga
    • 1aaa81b={random characters}
  • In HKEY_CURRENT_USER\Software\Microsoft\Uzahga
    • 1aaa81b={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\Identities
    • Last Username="Main Identity"
  • In HKEY_CURRENT_USER\Identities
    • Last User ID="{341F68BA-C841-4200-A7B4-3D5CFF202166}"
  • In HKEY_CURRENT_USER\Identities
    • Identity Login=9853
  • In HKEY_CURRENT_USER\Identities
    • Identity Ordinal=2
  • In HKEY_CURRENT_USER\Software\Microsoft\Uzahga
    • 9f82hc2="zKtQ9Q==_CHAR(0x07)__CHAR(0x03)_u_CHAR(0x0E)_"

Step 5

Search and delete these folders

[ 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\Geyj
  • %User Profile%\Application Data\Igojal

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%\Geyj\muhyc.exe
  • %User Profile%\Igojal\awceu.mea

Step 7

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