BKDR_INJECT.EJSH
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
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.
It connects to certain websites to send and receive information. However, as of this writing, the said sites are inaccessible. It deletes the initially executed copy of itself.
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.
Installation
This backdoor drops the following copies of itself into the affected system and executes them:
- %SYSTEM%\dnsaels.exe
It injects codes into the following process(es):
- explorer.exe
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
camosapi = %SYSTEM%\dnsaels.exe
Other System Modifications
This backdoor adds the following registry keys:
HKEY_CURRENT_USER\Software\AppDataLow\
F852C40F-F7F9-EA0E-41AC-1BBE05A07FD2
Other Details
This backdoor connects to the following website to send and receive information:
- {BLOCKED}omter.su
- {BLOCKED}orjution.su
- {BLOCKED}perkom.com
However, as of this writing, the said sites are inaccessible.
It deletes the initially executed copy of itself
NOTES:
This backdoor is capable of the following:
- Get system information
- Get cookies and browser profiles
- Get running process/services
- Get installed drivers
- Get installed programs
- Connect to remote site
- Download/Upload file
- Execute commands
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
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_CURRENT_USER\Software\AppDataLow
- F852C40F-F7F9-EA0E-41AC-1BBE05A07FD2
- F852C40F-F7F9-EA0E-41AC-1BBE05A07FD2
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\Windows\CurrentVersion\Run
- camosapi = "%SYSTEM%\dnsaels.exe"
- camosapi = "%SYSTEM%\dnsaels.exe"
Step 4
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_INJECT.EJSH. 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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