TROJ_MALEX.AA
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.
TECHNICAL DETAILS
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 drops the following copies of itself into the affected system:
- winlogons.exe
- c\svchost1.exe
- d\svchost2.exe
- e\svchost3.exe
- f\svchost4.exe
- g\svchost5.exe
- h\svchost6.exe
- wins\svchost.exe
It creates the following folders:
- c
- d
- e
- f
- g
- h
- wins
- WinAxA
Autostart Technique
This Trojan modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
shell = "Explorer.exe winlogons.exe"
(Note: The default value data of the said registry entry is Explorer.exe.)
Other System Modifications
This Trojan 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 2.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = "1"
(Note: The default value data of the said registry entry is 1.)
Dropping Routine
This Trojan drops the following files:
- winlogons.exe
- c\svchost1.exe
- d\svchost2.exe
- e\svchost3.exe
- f\svchost4.exe
- g\svchost5.exe
- h\svchost6.exe
- wins\svchost.exe
- %Windows%\c\svchost1.exe
- %Windows%\d\svchost2.exe
- %Windows%\e\svchost3.exe
- %Windows%\f\svchost4.exe
- %Windows%\g\svchost5.exe
- %Windows%\h\svchost6.exe
- All Users.exe
- Application Data.exe
- Adobe.exe
- Acrobat.exe
- 10.0.exe
- Replicate.exe
- Security.exe
- Setup.exe
- {AC76BA86-7AD7-1033-7B44-AA0000000001}.exe
- Microsoft.exe
- Crypto.exe
- DSS.exe
- MachineKeys.exe
- RSA.exe
- S-1-5-18.exe
- HTML Help.exe
- Media Index.exe
- Media Player.exe
- Network.exe
- Connections.exe
- Cm.exe
- Pbk.exe
- User Account Pictures.exe
- Default Pictures.exe
- Desktop.exe
- Documents.exe
- My Music.exe
- My Playlists.exe
- Sample Music.exe
- Sample Playlists.exe
- 0008044E.exe
- My Pictures.exe
- Sample Pictures.exe
- My Videos.exe
- DRM.exe
- Favorites.exe
- Start Menu.exe
- Programs.exe
- Accessories.exe
- Accessibility.exe
- Communications.exe
- Entertainment.exe
- System Tools.exe
- Administrative Tools.exe
- Games.exe
- Startup.exe
- WinPcap.exe
- Templates.exe
- Default User.exe
- Internet Explorer.exe
- SystemCertificates.exe
- My.exe
- Certificates.exe
- CRLs.exe
- CTLs.exe
- Cookies.exe
- Local Settings.exe
- Windows Media.exe
- 9.0.exe
- History.exe
- History.IE5.exe
- Temp.exe
- Temporary Internet Files.exe
- Content.IE5.exe
- 09RWHJQN.exe
- BVLBNMKH.exe
- ZDGZNKA5.exe
- ZSGKJKO6.exe
- My Documents.exe
- NetHood.exe
- PrintHood.exe
- Recent.exe
- SendTo.exe
- LocalService.exe
- Credentials.exe
- S-1-5-19.exe
- Windows.exe
- 246FT6TD.exe
- 9STOYKO4.exe
- NF72HY20.exe
- PHOM4UYK.exe
- NetworkService.exe
- S-1-5-20.exe
- Wilbert.exe
- Identities.exe
- {8A24C031-62FE-4BF5-94F0-BFD4FBCD674B}.exe
- S-1-5-21-1645522239-1292428093-682003330-1003.exe
- Quick Launch.exe
- MMC.exe
- Themes.exe
- Links.exe
- CD Burning.exe
- Microsoft .NET Framework 4 Setup_4.0.30319.exe
- Microsoft Visual C++ 2010 x86 Redistributable Setup_10.0.30319.exe
- {835818DD-220C-4ABD-946E-0D8660B95E29}.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
This report is generated via an automated analysis system.
SOLUTION
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
Identify and delete files detected as TROJ_MALEX.AA using either the Startup Disk or Recovery Console
Step 3
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 = ""2""
- From: Hidden = "2"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: HideFileExt = "1"
To: HideFileExt = ""1""
- From: HideFileExt = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: shell = "Explorer.exe winlogons.exe"
To: shell = ""Explorer.exe""
- From: shell = "Explorer.exe winlogons.exe"
Step 4
Search and delete these components
- winlogons.exe
- c\svchost1.exe
- d\svchost2.exe
- e\svchost3.exe
- f\svchost4.exe
- g\svchost5.exe
- h\svchost6.exe
- wins\svchost.exe
- %Windows%\c\svchost1.exe
- %Windows%\d\svchost2.exe
- %Windows%\e\svchost3.exe
- %Windows%\f\svchost4.exe
- %Windows%\g\svchost5.exe
- %Windows%\h\svchost6.exe
- All Users.exe
- Application Data.exe
- Adobe.exe
- Acrobat.exe
- 10.0.exe
- Replicate.exe
- Security.exe
- Setup.exe
- {AC76BA86-7AD7-1033-7B44-AA0000000001}.exe
- Microsoft.exe
- Crypto.exe
- DSS.exe
- MachineKeys.exe
- RSA.exe
- S-1-5-18.exe
- HTML Help.exe
- Media Index.exe
- Media Player.exe
- Network.exe
- Connections.exe
- Cm.exe
- Pbk.exe
- User Account Pictures.exe
- Default Pictures.exe
- Desktop.exe
- Documents.exe
- My Music.exe
- My Playlists.exe
- Sample Music.exe
- Sample Playlists.exe
- 0008044E.exe
- My Pictures.exe
- Sample Pictures.exe
- My Videos.exe
- DRM.exe
- Favorites.exe
- Start Menu.exe
- Programs.exe
- Accessories.exe
- Accessibility.exe
- Communications.exe
- Entertainment.exe
- System Tools.exe
- Administrative Tools.exe
- Games.exe
- Startup.exe
- WinPcap.exe
- Templates.exe
- Default User.exe
- Internet Explorer.exe
- SystemCertificates.exe
- My.exe
- Certificates.exe
- CRLs.exe
- CTLs.exe
- Cookies.exe
- Local Settings.exe
- Windows Media.exe
- 9.0.exe
- History.exe
- History.IE5.exe
- Temp.exe
- Temporary Internet Files.exe
- Content.IE5.exe
- 09RWHJQN.exe
- BVLBNMKH.exe
- ZDGZNKA5.exe
- ZSGKJKO6.exe
- My Documents.exe
- NetHood.exe
- PrintHood.exe
- Recent.exe
- SendTo.exe
- LocalService.exe
- Credentials.exe
- S-1-5-19.exe
- Windows.exe
- 246FT6TD.exe
- 9STOYKO4.exe
- NF72HY20.exe
- PHOM4UYK.exe
- NetworkService.exe
- S-1-5-20.exe
- Wilbert.exe
- Identities.exe
- {8A24C031-62FE-4BF5-94F0-BFD4FBCD674B}.exe
- S-1-5-21-1645522239-1292428093-682003330-1003.exe
- Quick Launch.exe
- MMC.exe
- Themes.exe
- Links.exe
- CD Burning.exe
- Microsoft .NET Framework 4 Setup_4.0.30319.exe
- Microsoft Visual C++ 2010 x86 Redistributable Setup_10.0.30319.exe
- {835818DD-220C-4ABD-946E-0D8660B95E29}.exe
Step 5
Search and delete these folders
- c
- d
- e
- f
- g
- h
- wins
- WinAxA
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_MALEX.AA. 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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