Backdoor.MSIL.NJRAT.L

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.

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 adds the following processes:

• http://go.{BLOCKED}oft.com/fwlink/?{random characters}(null)&processName={malware file name}.exe&platform=0009&osver=5&isServer=0&shimver=4.0.30319.34209
• "%Program Files%\Internet Explorer\IEXPLORE.EXE" SCODEF:2600 CREDAT:275457 /prefetch:2

It creates the following folders:

• %Application Data%\Microsoft\Windows\DNTException
• %Application Data%\Microsoft\Windows\IECompatUACache
• %Application Data%\Microsoft\Windows\IECompatCache
• %AppDataLocal%\Microsoft\Internet Explorer\DomainSuggestions
• %AppDataLocal%\Microsoft\Internet Explorer\Recovery\High\Active
• %Application Data%\Microsoft\Windows\PrivacIE

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other System Modifications

This Backdoor deletes the following files:

• %AppDataLocal%Low\Microsoft\Internet Explorer\Services\search_{0633EE93-D776-472f-A0FF-E1416B8B2E3A}.ico

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Dropping Routine

This Backdoor drops the following files:

• %User Temp%\dtr.gf
• %AppDataLocal%\Microsoft\Internet Explorer\imagestore\joppu72\imagestore.dat
• %AppDataLocal%\Microsoft\Internet Explorer\DOMStore\3UYAQU1F\docs.microsoft[1].xml
• %AppDataLocal%\Microsoft\Internet Explorer\Recovery\High\Active\RecoveryStore.{1BE2444E-0291-11EA-9A18-005056BC35FC}.dat
• %AppDataLocal%\Microsoft\Internet Explorer\Recovery\High\Active\{25EAB115-0291-11EA-9A18-005056BC35FC}.dat
• %AppDataLocal%\Microsoft\Internet Explorer\MSIMGSIZ.DAT
• %AppDataLocal%\Microsoft\Internet Explorer\Recovery\High\Active\{25EAB116-0291-11EA-9A18-005056BC35FC}.dat
• %AppDataLocal%\Microsoft\Internet Explorer\DomainSuggestions\en-US.6

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

This report is generated via an automated analysis system.