TROJ_DLOADR.YYMK
Trojan horse Downloader.Banload2.TBC (AVG)
Windows
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
117,760 bytes
EXE
No
06 Dec 2014
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 creates the following folders:
- %User Profile%\Microsoft\Google
- %User Profile%\Network\Downloader
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
Other System Modifications
This Trojan deletes the following files:
- %Windows%\SoftwareDistribution\DataStore\Logs\edbtmp.log
(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
It adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Tracing\
Microsoft\BITS
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Tracing\
Microsoft\BITS\CtlGuid
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\BITS
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Tracing\
Microsoft\BITS
LogSessionName = "stdout"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Tracing\
Microsoft\BITS
Active = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Tracing\
Microsoft\BITS
ControlFlags = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Tracing\
Microsoft\BITS\CtlGuid
Guid = "4a8aaa94-cfc4-46a7-8e4e-17bc45608f0a"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Tracing\
Microsoft\BITS\CtlGuid
BitNames = "{random characters}"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\BackupRestore\FilesNotToBackup
BITS_metadata = "%User Profile%\Downloader\*"
Dropping Routine
This Trojan drops the following files:
- %System%\bitsadmin.exe
- %Windows%\Tasks\Adobe Update.job
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
Other Details
This Trojan connects to the following possibly malicious URL:
- {BLOCKED}.164.101
This report is generated via an automated analysis system.
SOLUTION
9.700
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
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Tracing\Microsoft
- BITS
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Tracing\Microsoft\BITS
- CtlGuid
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
- BITS
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 NT\CurrentVersion\Tracing\Microsoft\BITS
- LogSessionName = "stdout"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Tracing\Microsoft\BITS
- Active = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Tracing\Microsoft\BITS
- ControlFlags = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Tracing\Microsoft\BITS\CtlGuid
- Guid = "4a8aaa94-cfc4-46a7-8e4e-17bc45608f0a"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Tracing\Microsoft\BITS\CtlGuid
- BitNames = "{random characters}"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\BackupRestore\FilesNotToBackup
- BITS_metadata = "%User Profile%\Downloader\*"
Step 4
Search and delete these components
- %System%\bitsadmin.exe
- %Windows%\Tasks\Adobe Update.job
Step 5
Search and delete these folders
- %User Profile%\Microsoft\Google
- %User Profile%\Network\Downloader
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOADR.YYMK. 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 7
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.
- %Windows%\SoftwareDistribution\DataStore\Logs\edbtmp.log
Did this description help? Tell us how we did.