TROJ_DROPPER.ZYG
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
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
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 deletes the following files:
- %User Temp%\58e0ef.mst
- %User Temp%\AdobeARM.log
- %User Temp%\AdobeSFX.log
- %User Temp%\ASPNETSetup_00000.log
- %User Temp%\ASPNETSetup_00001.log
- %User Temp%\ASPNETSetup_00002.log
- %User Temp%\dd_depcheck_NETFX_EXP_35.txt
- %User Temp%\dd_dotnetfx35error.txt
- %User Temp%\dd_dotnetfx35install.txt
- %User Temp%\dd_dotNetFx40_Full_x86_x64_decompression_log.txt
- %User Temp%\dd_MSXML6_MSI0686.txt
- %User Temp%\dd_netfx20MSI7F16.txt
- %User Temp%\dd_netfx20UI7F16.txt
- %User Temp%\dd_NET_Framework20_Setup06A7.txt
- %User Temp%\dd_NET_Framework30_Setup0775.txt
- %User Temp%\dd_NET_Framework35_MSI07B9.txt
- %User Temp%\dd_RGB9RAST_x86.msi0683.txt
- %User Temp%\dd_vcredistMSI3CAA.txt
- %User Temp%\dd_vcredistMSI7C21.txt
- %User Temp%\dd_vcredistUI3CAA.txt
- %User Temp%\dd_vcredistUI7C21.txt
- %User Temp%\dd_wcf_CA_smci_20111017_044900_062.txt
- %User Temp%\dd_wcf_retCA29BA.txt
- %User Temp%\dd_WIC.txt
- %User Temp%\dd_XPS.txt
- %User Temp%\Microsoft .NET Framework 4 Setup_20111016_234618578-MSI_netfx_Core_x86.msi.txt
- %User Temp%\Microsoft .NET Framework 4 Setup_20111016_234618578-MSI_netfx_Extended_x86.msi.txt
- %User Temp%\Microsoft .NET Framework 4 Setup_20111016_234618578.html
- %User Temp%\Microsoft Visual C++ 2010 x86 Redistributable Setup_20111020_000954642-MSI_vc_red.msi.txt
- %User Temp%\Microsoft Visual C++ 2010 x86 Redistributable Setup_20111020_000954642.html
- %User Temp%\uxeventlog.txt
- %User Temp%\vminst.log_20111016_212239_Failed.log
- %User Temp%\vminst.log_20130313_012028.log
- %User Temp%\vminst.log_20130313_012352_Failed.log
- %User Temp%\vmmsi.log_20111016_212246_Failed.log
- %User Temp%\vmmsi.log_20130313_012028.log
- %User Temp%\vmmsi.log_20130313_012352_Failed.log
- %User Temp%\WSFF8.tmp
- %User Temp%\WSFF9.tmp
- %User Temp%\tmp3.tmp
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
Other Details
This Trojan deletes itself after execution.
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
Scan your computer with your Trend Micro product to delete files detected as TROJ_DROPPER.ZYG. 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.
Step 3
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %User Temp%\58e0ef.mst
- %User Temp%\AdobeARM.log
- %User Temp%\AdobeSFX.log
- %User Temp%\ASPNETSetup_00000.log
- %User Temp%\ASPNETSetup_00001.log
- %User Temp%\ASPNETSetup_00002.log
- %User Temp%\dd_depcheck_NETFX_EXP_35.txt
- %User Temp%\dd_dotnetfx35error.txt
- %User Temp%\dd_dotnetfx35install.txt
- %User Temp%\dd_dotNetFx40_Full_x86_x64_decompression_log.txt
- %User Temp%\dd_MSXML6_MSI0686.txt
- %User Temp%\dd_netfx20MSI7F16.txt
- %User Temp%\dd_netfx20UI7F16.txt
- %User Temp%\dd_NET_Framework20_Setup06A7.txt
- %User Temp%\dd_NET_Framework30_Setup0775.txt
- %User Temp%\dd_NET_Framework35_MSI07B9.txt
- %User Temp%\dd_RGB9RAST_x86.msi0683.txt
- %User Temp%\dd_vcredistMSI3CAA.txt
- %User Temp%\dd_vcredistMSI7C21.txt
- %User Temp%\dd_vcredistUI3CAA.txt
- %User Temp%\dd_vcredistUI7C21.txt
- %User Temp%\dd_wcf_CA_smci_20111017_044900_062.txt
- %User Temp%\dd_wcf_retCA29BA.txt
- %User Temp%\dd_WIC.txt
- %User Temp%\dd_XPS.txt
- %User Temp%\Microsoft .NET Framework 4 Setup_20111016_234618578-MSI_netfx_Core_x86.msi.txt
- %User Temp%\Microsoft .NET Framework 4 Setup_20111016_234618578-MSI_netfx_Extended_x86.msi.txt
- %User Temp%\Microsoft .NET Framework 4 Setup_20111016_234618578.html
- %User Temp%\Microsoft Visual C++ 2010 x86 Redistributable Setup_20111020_000954642-MSI_vc_red.msi.txt
- %User Temp%\Microsoft Visual C++ 2010 x86 Redistributable Setup_20111020_000954642.html
- %User Temp%\uxeventlog.txt
- %User Temp%\vminst.log_20111016_212239_Failed.log
- %User Temp%\vminst.log_20130313_012028.log
- %User Temp%\vminst.log_20130313_012352_Failed.log
- %User Temp%\vmmsi.log_20111016_212246_Failed.log
- %User Temp%\vmmsi.log_20130313_012028.log
- %User Temp%\vmmsi.log_20130313_012352_Failed.log
- %User Temp%\WSFF8.tmp
- %User Temp%\WSFF9.tmp
- %User Temp%\tmp3.tmp
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