Backdoor:W32/Agent.DQLR

Classification

Malware

Backdoor

W32

Agent.DQLR, Trojan-Dropper:W32/Agent.DQLQ

Summary

Backdoor:W32/Agent.DLQR is a backdoor program created by an attacker using a malware creation kit. It may be dropped onto a target computer system by a separate dropper program (detected as Trojan-Dropper:W32/Agent.DQLQ).

Removal

Automatic action

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

Suspect a file is incorrectly detected (a False Positive)?

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest detection database updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    NOTE If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note You need administrative rights to change the settings.

Find out more

Knowledge Base

Find the latest advice in our Community Knowledge Base.

User Guide

See the user guide for your product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details

As its payload, the backdoor drops a DLL file that provides an external attacker control over the compromised machine. The file is partially encrypted with very simple XOR-key encryption. It is not polymorphic.

The DLL is dropped in one of the following locations:

  • %windir%
  • windir\system32
  • %systemroot%
  • %systemroot%\system32
  • %userprofile%
  • %alluserprofile%
  • %appdata%
  • %commonprogramfiles%
  • %programfiles%
  • %temp

The specific location is defined by the attacker when the backdoor is created, as is the name for the DLL file. The name may be random.

Once dropped, the DLL will connect to a remote command and control (C and C) server, giving an external attacker extensive control over the infected computer by offering a file browser, command prompt and a registry browser. The address of the server is also defined by the attacker and may therefore vary.

More

This malware is also discussed in a white paper from McAfee:

  • http://www.mcafee.com/us/resources/white-papers/wp-global-energy-cyberattacks-night-dragon.pdf

Network Traffic

If a network infection is suspected, infected machines may be found by inspecting the network traffic.

Machines that are currently connected to the command and control server will send the following network traffic:

  • (Example of this tcp-packet in hex format) 03 50 00 00 00 00 00 00 00 00 00 00 68 57 24 13

According to the McAfee paper, the following regular expression can be used to find those packages:

  • \x03\x50[\x00-\xff]+\x68\x57\x24\x13

Machines that have not been able to connect to the command and control server will send the following network traffic:

  • (Example of this tcp-packet in hex format) 01 50 00 00 00 00 00 00 00 00 00 01 68 57 24 13

According to the McAfee paper, the following regular expression can be used to find those packages:

  • \x01\x50[\x00-\xff]+\x68\x57\x24\x13

If these suspect samples are found, please send them to our Submit A Sample (SAS) page for further investigation.