BKDR_EMDIVI.SMA
Windows
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
However, as of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
Arrival Details
This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Autostart Technique
This backdoor modifies the following registry entry(ies) to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "%System%\userinit.exe,{malware path}\{malware name},"
(Note: The default value data of the said registry entry is "%System%\userinit.exe,".)
Other Details
This backdoor connects to the following possibly malicious URL:
- http://www.{BLOCKED}ye.co.jp/blog/2014/index.php
- http://www.{BLOCKED}urin.or.jp/htm/copyright/folder/sc_flash/index.php
- http://www.{BLOCKED}o-ton.com/koushi/detail/sc_flash/index.php
However, as of this writing, the said sites are inaccessible.
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
Scan your computer with your Trend Micro product and note files detected as BKDR_EMDIVI.SMA
Step 4
Restart in Safe Mode
Step 5
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: Userinit = "%System%\userinit.exe,{malware path}\{malware name},"
To: Userinit = "%System%\userinit.exe,"
- From: Userinit = "%System%\userinit.exe,{malware path}\{malware name},"
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_EMDIVI.SMA. 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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