BKDR_PRESHIN.AB
TrojanProxy:Win32/Preshin.B(Microsoft), Win32/TrojanProxy.Preshin.B trojan(Eset)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This backdoor may be dropped by other malware. It arrives as a component bundled with malware/grayware packages.
It does not have any propagation routine.
It executes commands from a remote malicious user, effectively compromising the affected system. However, as of this writing, the said sites are inaccessible.
As of this writing, the said sites are inaccessible.
It steals certain information from the system and/or the user.
TECHNICAL DETAILS
Arrival Details
This backdoor may be dropped by other malware.
It arrives as a component bundled with malware/grayware packages.
Installation
This backdoor drops the following files:
- {malware file name}.{malware extension}-KLMP.pf
It adds the following processes:
- iexplore.exe
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- Ultro_ISO_0369
Propagation
This backdoor does not have any propagation routine.
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- Download File
- Download and Execute File
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- http://www.{BLOCKED}p.caedufjf.net/my/logon.php?000932{random characters}
However, as of this writing, the said sites are inaccessible.
Download Routine
This backdoor connects to the following URL(s) to download its component file(s):
- http://www.{BLOCKED}p.caedufjf.net/my/logon.php?000932{random characters}
It saves the files it downloads using the following names:
- %User Temp%\iacup.dat
(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.)
As of this writing, the said sites are inaccessible.
Information Theft
This backdoor steals the following information:
- Host Name
- Local IP Address
- OS Version
Stolen Information
This backdoor saves the stolen information in the following file:
- %User Temp%\wg.dat - will be deleted afterwards
(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 backdoor connects to the following URL(s) to check for an Internet connection:
- www.google.com
NOTES:
For this malware to execute properly, it should be run by any of these processes:
- rundll32.exe
- iexplore.exe
- firefox.exe
This malware also connects to www.google.com to download and save the file as %User Temp%\losivp.tmp and deletes it afterwards.
It does not have rootkit capabilities.
It does not exploit any vulnerability.
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 and note files detected as BKDR_PRESHIN.AB
Step 3
Restart in Safe Mode
Step 4
Search and delete these files
- %User Temp%\iacup.dat
- %User Temp%\losivp.tmp
- {malware file name}.{malware extension}-KLMP.pf
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_PRESHIN.AB. 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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