TROJ_PROXYCHG.AJ
ERROR (Sunbelt)
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.
Other System Modifications
This Trojan adds the following registry keys:
HKEY_USERS\S-1-5-21-1645522239-1292428093-682003330-1003\Software\
Microsoft\Internet Explorer\Privacy
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
SystemCertificates\ROOT\Certificates\
4E44E7573B9B10C6F1EEE95CFE11BD7F83D4C7AC
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings
AutoConfigURL = "http://{BLOCKED}z.com/Bg43ZV623/proxy.pac"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
AutoConfigURL = "http://{BLOCKED}z.com/Bg43ZV623/proxy.pac"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
ClearBrowsingHistoryOnExit = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
CleanTIF = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
UseAllowList = "0"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
SystemCertificates\ROOT\Certificates\
4E44E7573B9B10C6F1EEE95CFE11BD7F83D4C7AC
Blob = "{random values}"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Connections
DefaultConnectionSettings = "{random values}"
(Note: The default value data of the said registry entry is {random values}.)
This report is generated via an automated analysis system.
SOLUTION
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
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_USERS\S-1-5-21-1645522239-1292428093-682003330-1003\Software\Microsoft\Internet Explorer
- Privacy
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\ROOT\Certificates
- 4E44E7573B9B10C6F1EEE95CFE11BD7F83D4C7AC
Step 3
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings
- AutoConfigURL = "http://{BLOCKED}z.com/Bg43ZV623/proxy.pac"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- AutoConfigURL = "http://{BLOCKED}z.com/Bg43ZV623/proxy.pac"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Privacy
- ClearBrowsingHistoryOnExit = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Privacy
- CleanTIF = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Privacy
- UseAllowList = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\ROOT\Certificates\4E44E7573B9B10C6F1EEE95CFE11BD7F83D4C7AC
- Blob = "{random values}"
Step 4
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\Connections
- From: DefaultConnectionSettings = "{random values}"
To: DefaultConnectionSettings = ""{random values}""
- From: DefaultConnectionSettings = "{random values}"
Step 5
Scan your computer with your Trend Micro product to delete files detected as TROJ_PROXYCHG.AJ. 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.
Did this description help? Tell us how we did.