TROJ_DLOADER.ALX
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
When executed, this malware connects to certain URLs where it downloads another file.
This Trojan may be unknowingly downloaded by a user while visiting malicious websites.
TECHNICAL DETAILS
49,152 bytes
EXE
Yes
22 Mar 2011
Downloads files
Arrival Details
This Trojan may be unknowingly downloaded by a user while visiting malicious websites.
Other System Modifications
This Trojan adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\PhishingFilter
Enabled = 1
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\PhishingFilter
ShownVerifyBalloon = 3
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Check_Associations = no
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
WarnonZoneCrossing = 0
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
WarnOnPostRedirect = 0
NOTES:
Upon execution, it pauses for five minutes before proceeding with infection.
It then connects to the following URLs where it downloads another file:
- http://www.news.{BLOCKED}v.com
- http://software.{BLOCKED}a.com
It appends the following to the above-mentioned URLs:
- /acheb.aspx?Random={parameter}
- /bajree.aspx?Random={parameter}
- /cyacrin.aspx?Random={parameter}
- /dauber.aspx?Random={parameter}
- /eaves.aspx?Random={parameter}
- /kavie.aspx?i5={parameter}
- /lopper.aspx?i5={parameter}
- /mabel.aspx?i5={parameter}
- /noral.aspx?i5={parameter}
- /opaci.aspx?i5={parameter}
- /fructi.aspx?e1={parameter}
- /gynae.aspx?e1={parameter}
- /hoard.aspx?e1={parameter}
- /iodal.aspx?e1={parameter}
- /jiang.aspx?e1={parameter}
- &g3=yes&h4={parameter}
- &g3=no&h4={parameter}
where {parameter} is a base64 encoded data that contains the following:
- browser
- computer name
- date and time of installation
- email clients
- IP address
The downloaded file is saved as %User Temp%\wmupdate.tmp and executed afterwards. As a result, the malicious routines of the downloaded file are also exhibited on the system. As of this writing, no files are downloaded.
SOLUTION
9.200
7.918.01
22 Mar 2011
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
Identify and terminate files detected as TROJ_DLOADER.ALX
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
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_CURRENT_USER\Software\Microsoft\Internet Explorer\PhishingFilter
- Enabled = 1
- Enabled = 1
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\PhishingFilter
- ShownVerifyBalloon = 3
- ShownVerifyBalloon = 3
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
- Check_Associations = no
- Check_Associations = no
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- WarnonZoneCrossing = 0
- WarnonZoneCrossing = 0
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- WarnOnPostRedirect = 0
- WarnOnPostRedirect = 0
Step 4
Search and delete these files
Step 5
Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOADER.ALX. 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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