KoiLoader Reloaded: New Variant Uses LNK Abuse, Script Chains, and PowerShell to Deliver Stealer Payload

Summary: TRUeSentire’s Threat Response Unit has identified an advanced KoiLoader malware intrusion attempting to compromise systems through a phishing email. The attack leverages misleading file formats, manipulates PowerShell commands, and employs multiple anti-detection techniques to deploy the Koi Stealer for extensive data theft. KoiLoader exemplifies sophisticated malware engineering, utilizing custom cryptographic channels for Command and Control (C&C) operations.

Affected: Organizations susceptible to phishing attacks and malware infections

Keypoints :

  • Intrusion begins with a phishing email containing a deceptive ZIP attachment.
  • KoiLoader employs a Windows bug to conceal command arguments, launching hidden PowerShell commands.
  • KoiStealer is designed to extract sensitive data, including saved passwords and browser information.
  • Unique persistence mechanisms and anti-detection techniques make KoiLoader challenging to combat.
  • TRU has released an emulation toolkit for researchers to simulate the malware’s C2 traffic.

Source: https://securityonline.info/koiloader-reloaded-new-variant-uses-lnk-abuse-script-chains-and-powershell-to-deliver-stealer-payload/