Redosdru.V Malware that hides in encrypted DLL files to avoid detection by Firewalls (May 11,2016)

The Dell Sonicwall Threats Research team observed reports of a New Malware family named GAV: Redosdru.V actively spreading in the wild. This time attackers used a dropper to download the original Malware that hides in encrypted DLL files to avoid detection by Firewalls.

Infection Cycle:

Md5:

• 807db66fd414f3eb5e74e10fc4309ae3

The Malware adds the following files to the system:

• Malware.exe

  • C:Program FilesAppPatchNetsyst96.dll

  • C:Program FilesMicrosoft FduoodFduzjyw.exe

The Trojan adds the following keys to the Windows registry to ensure persistence upon reboot:

• HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun

  • Wsejti gzuaqwud=C:Program FilesMicrosoft FduoodFduzjyw.exe

Once the computer is compromised, the malware copies its own files to AppPatch folder.

The Malware tries to download encrypted DLL file from its own C&C server from following domain:

Here is an example of encrypted DLL file:

Command and Control (C&C) Traffic

Redosdru.V performs communication over 9925 and 60321 ports. The malware sends your system information to its own C&C server via following format, here is an example:

We have been monitoring varying hits over the past few days for the signature that blocks this threat:

SonicWALL Gateway AntiVirus provides protection against this threat via the following signature:

• GAV: Redosdru.V (Trojan)

Security News

The SonicWall Capture Labs Threat Research Team gathers, analyzes and vets cross-vector threat information from the SonicWall Capture Threat network, consisting of global devices and resources, including more than 1 million security sensors in nearly 200 countries and territories. The research team identifies, analyzes, and mitigates critical vulnerabilities and malware daily through in-depth research, which drives protection for all SonicWall customers. In addition to safeguarding networks globally, the research team supports the larger threat intelligence community by releasing weekly deep technical analyses of the most critical threats to small businesses, providing critical knowledge that defenders need to protect their networks.