TROJ_CVE20151641.BZD
Exploit:Win32/CVE-2015-1641 (Microsoft), Win32/Exploit.CVE-2015-1641.H (ESET), Exploit.CVE-2015-1641.Gen (F-Secure)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
It takes advantage of software vulnerabilities in certain software to drop malicious files.
TECHNICAL DETAILS
Arrival Details
This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
Dropping Routine
This Trojan drops the following files:
- %Application Data%\btecache.dll
- %All Users Profile%\svchost.dll
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.. %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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.)
It takes advantage of unknown vulnerabilities in the following software to drop malicious files:
Other Details
This Trojan does the following:
- It creates the following autostart registry entry to execute the dropped file:
- HKEY_CURRENT_USER\Software\Microsoft\Office test\Special\Perf
{Default) = "%Application Data%\btecache.dll"
- HKEY_CURRENT_USER\Software\Microsoft\Office test\Special\Perf
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)
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
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
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\Office test\Special\Perf
- (Default) = "%Application Data%\btecache.dll"
- (Default) = "%Application Data%\btecache.dll"
Step 4
Search and delete this file
Step 5
Scan your computer with your Trend Micro product to delete files detected as TROJ_CVE20151641.BZD. 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 6
Download and apply this security patch Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors.
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