TROJ_SMALL.WRRS
TR/Crypt.ZPACK.Gen (Avira)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
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 does not have any propagation routine.
It does not have any backdoor routine.
As of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
16,384 bytes
EXE
Delphi
Yes
30 Jun 2015
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 drops the following non-malicious files:
- %User Temp%\CVRB53A.tmp.cvr – contains the current date
- %User Temp%\CVRAC00.tmp.cvr – contains error code
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
Propagation
This Trojan does not have any propagation routine.
Backdoor Routine
This Trojan does not have any backdoor routine.
Download Routine
This Trojan connects to the following URL(s) to download its configuration file:
- http://{BLOCKED}ke.{BLOCKED}rhub.org/links/page{value}.html
It saves the files it downloads using the following names:
- %User Temp%\CVRC96A.tmp.cvr - contains encrypted information which is decrypted after
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
As of this writing, the said sites are inaccessible.
Information Theft
This Trojan gathers the following data:
- current date
- value derived from host name
SOLUTION
9.750
11.762.03
30 Jun 2015
11.763.00
01 Jul 2015
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
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Identify and terminate files detected as TROJ_SMALL.WRRS
- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- 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 4
Search and delete these files
- %User Temp%\CVRB53A.tmp.cvr
- %User Temp%\CVRAC00.tmp.cvr
- %User Temp%\CVRC96A.tmp.cvr
Step 5
Scan your computer with your Trend Micro product to delete files detected as TROJ_SMALL.WRRS. 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.