{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/muddywater/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":["MuddyWater"],"_cs_cves":[],"_cs_exploited":false,"_cs_products":["Splunk Enterprise","Splunk Enterprise Security","Splunk Cloud","Google Update"],"_cs_severities":["high"],"_cs_tags":["muddywater","powgoop","dll-sideloading","powershell","c2","beacon"],"_cs_type":"threat","_cs_vendors":["Google","Splunk"],"content_html":"\u003cp\u003eThe detection identifies a specific stage in the MuddyWater (also known as SeedWorm, Static Kitten, and MERCURY) infection chain, focusing on the execution of the PowGoop loader. MuddyWater has been actively using PowGoop since at least 2020 as their primary initial access method. PowGoop abuses DLL side-loading, specifically targeting a fake GoogleUpdate.exe, to initiate a multi-stage decoding process. This ultimately leads to the deployment of a fully functional PowerShell backdoor disguised with a benign extension. The backdoor uses a config.txt file that contains a hardcoded C2 address and victim GUID. The malware beacons via modified base64-encoded HTTP, attempting to blend C2 traffic with legitimate Google Update processes to evade network-based detections.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eInitial access is achieved through an unknown vector (e.g., spearphishing) leading to the execution of a malicious DLL.\u003c/li\u003e\n\u003cli\u003eThe malicious DLL is sideloaded by a fake GoogleUpdate.exe, masquerading as a legitimate Google application.\u003c/li\u003e\n\u003cli\u003eThe DLL initiates a multi-stage decoding chain to decrypt and execute a PowerShell script.\u003c/li\u003e\n\u003cli\u003eThe PowerShell script reads a \u003ccode\u003econfig.txt\u003c/code\u003e file containing a hardcoded C2 address and victim GUID.\u003c/li\u003e\n\u003cli\u003eThe PowerShell script decodes the C2 address from the config file to establish command and control.\u003c/li\u003e\n\u003cli\u003ePowerShell uses FromBase64String to decode the payload.\u003c/li\u003e\n\u003cli\u003eThe PowerShell backdoor establishes persistence and begins beaconing to the C2 server via modified base64-encoded HTTP requests.\u003c/li\u003e\n\u003cli\u003eThe attacker uses the established C2 channel to perform reconnaissance, lateral movement, and data exfiltration.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eA successful PowGoop infection allows MuddyWater to gain persistent access to the compromised system. This access can be leveraged for a variety of malicious activities, including data theft, espionage, and further propagation of malware within the network. MuddyWater has been linked to numerous cyber espionage campaigns targeting government and commercial entities, particularly in the Middle East. The group\u0026rsquo;s activities pose a significant risk to organizations seeking to protect sensitive information and maintain operational integrity.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eEnable Sysmon Event ID 1 (process creation) logging to capture the necessary process execution details for the Sigma rules provided.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rules in this brief to your SIEM and tune for your environment.\u003c/li\u003e\n\u003cli\u003eInvestigate any PowerShell processes spawned by rundll32.exe that decode base64 strings and reference \u003ccode\u003econfig.txt\u003c/code\u003e, as highlighted in the rule \u0026ldquo;Detect Windows PowGoop Beacon Decoding via CommandLine\u0026rdquo;.\u003c/li\u003e\n\u003cli\u003eMonitor network traffic for base64-encoded HTTP requests originating from the Google Update process, as this is a technique used by PowGoop to mask C2 communications.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-03T12:00:00Z","date_published":"2024-01-03T12:00:00Z","id":"/briefs/2024-01-powgoop-beacon/","summary":"This detection identifies a DLL decoding and executing the PowGoop config.txt payload, indicating a stage in the MuddyWater infection chain where an obfuscated PowerShell beacon is unwrapped and live C2 communication starts.","title":"MuddyWater PowGoop Beacon Decoding Detection","url":"https://feed.craftedsignal.io/briefs/2024-01-powgoop-beacon/"}],"language":"en","title":"CraftedSignal Threat Feed — Muddywater","version":"https://jsonfeed.org/version/1.1"}