XLoader Execution via JAR Signing Tool (jarsigner.exe)

Summary:

AhnLab Security Intelligence Center (ASEC) has reported the distribution of XLoader malware utilizing DLL side-loading techniques. This method involves placing a malicious DLL alongside a legitimate application, allowing the malware to execute when the application runs. The attack leverages a legitimate file from the Eclipse Foundation, jarsigner, and includes malicious files that perform decryption and injection of the XLoader payload.

Keypoints:

  • AhnLab SEcurity intelligence Center (ASEC) identified XLoader malware distribution.
  • The attack uses DLL side-loading techniques.
  • Legitimate application involved is jarsigner from the Eclipse Foundation.
  • Malicious files include jli.dll and concrt140e.dll.
  • Documents2012.exe is a renamed legitimate file that loads the malicious DLL.
  • The malicious jli.dll has tampered export functions that execute threat actor’s functions.
  • concrt140e.dll serves as an encrypted payload for XLoader malware.
  • XLoader malware steals sensitive information and can download additional malware.
  • Users should be cautious of files distributed with executable files.

MITRE Techniques

  • DLL Side-Loading (T1218.011): Utilizes a legitimate application to load a malicious DLL, enabling execution of the malware.
  • Credential Dumping (T1003): XLoader malware may collect sensitive information from the user’s system.

IoC:

  • [File Hash] 42f5b18d194314f43af6a31d05e96f16
  • [File Hash] 8e6763e7922215556fa10711e1328e08
  • [URL] http[:]//www[.]datarush[.]life/uhtg/


Full Research: https://asec.ahnlab.com/en/84574/