{
	"id": "8566bec2-778f-4866-8f5d-3a341bb5a11f",
	"created_at": "2026-04-06T01:31:04.948793Z",
	"updated_at": "2026-04-10T03:24:23.692663Z",
	"deleted_at": null,
	"sha1_hash": "03886138f3327688bb10f999fb9fcf78973aac83",
	"title": "Gootloader Malware Leads to Cobalt Strike and Hand-on-Keyboard Activity",
	"llm_title": "",
	"authors": "",
	"file_creation_date": "0001-01-01T00:00:00Z",
	"file_modification_date": "0001-01-01T00:00:00Z",
	"file_size": 2202955,
	"plain_text": "Gootloader Malware Leads to Cobalt Strike and Hand-on-Keyboard Activity\r\nBy eSentire Threat Response Unit (TRU)\r\nArchived: 2026-04-06 00:20:13 UTC\r\nAdversaries don’t work 9-5 and neither do we. At eSentire, our 24/7 SOCs are staffed with Elite Threat Hunters\r\nand Cyber Analysts who hunt, investigate, contain and respond to threats within minutes.\r\nWe have discovered some of the most dangerous threats and nation state attacks in our space – including the\r\nKaseya MSP breach and the more_eggs malware.\r\nOur Security Operations Centers are supported with Threat Intelligence, Tactical Threat Response and Advanced\r\nThreat Analytics driven by our Threat Response Unit – the TRU team.\r\nIn TRU Positives, eSentire’s Threat Response Unit (TRU) provides a summary of a recent threat investigation. We\r\noutline how we responded to the confirmed threat and what recommendations we have going forward.\r\nHere’s the latest from our TRU Team…\r\nWhat did we find?\r\nWe uncovered Gootloader malware using a new infection technique, which helped further insights into the\r\nthreat actor(s) tools and next infection phase.\r\nGootloader’s initial JavaScript payload was delivered using the same technique via a compromised\r\nWordPress website.\r\nFigure 1: Compromised WordPress site serving the initial payload\r\nBased on the sample retrieved from the infected webpage, the initial payload creates several files under a\r\nlegitimate folder inAppData\\Roaming:\r\nhttps://www.esentire.com/blog/gootloader-leads-to-cobalt-strike-and-hand-on-keyboard-activity\r\nPage 1 of 8\n\nParliamentary Procedure.log (Engineering Geology.log on the infected machine)\r\nTIBCO Rendezvous.js (Custom Built-ins.js on the infected machine)\r\nIt is worth mentioning that the filenames and scheduled task name can be different even if the initial payload was\r\ndownloaded from the same infected webpage.\r\nThe scheduled task “Foreign Languages” is also created to run the “TIBCO Rendezvous.js” file with\r\nTIBCOR~1.JS argument at the log on from the sample we retrieved.\r\nApproximately 2 hours after the initial infection, we observed hands-on activity on the system. The threat\r\nactor(s) deployed a Cobalt Strike payload via the existing PowerShell process that beaconed out to several\r\ndomains with /GET /xmlrpc.php requests (e.g. hxxps[://]thetripgoeson[.]com/xmlrpc[.]php).\r\nThe next stage of Gootloader (threat actor(s)’ hands-on activity)\r\nThe threat actor(s) retrieved and ran the Cobalt Strike payload zieu.ps1 from path appdata\\roaming\\btbh\\.\r\nFigure 2: Retrieved zieu.ps1 Cobalt Strike payload\r\nAfter establishing the connection with the Cobalt Strike server (91.215.85[.]176), the threat actor(s) proceeded\r\nwith retrieving and extracting BloodHound, a tool used for graphically analyzing Active Directory and other\r\nidentity systems to identify attack pathways (20230103151757_bloodhound.zip) that contained pshound.ps1 under\r\nC:\\Users\\\u003cusername\u003e.\r\nAfter further analyzing the Windows Event Logs, we concluded that the script is similar to the one mentioned by\r\nGuidePoint Security that appears to be a BloodHound executable.\r\nBesides the Cobalt Strike payload, the threat actor(s) retrieved the following files/tools:\r\nPsExec (C:\\Users\\) – a command-line tool used to execute processes on remote computers, enabling\r\nadministrators to remotely control other systems on a network.\r\nhttps://www.esentire.com/blog/gootloader-leads-to-cobalt-strike-and-hand-on-keyboard-activity\r\nPage 2 of 8\n\nnwu2ndiyotmtmdvmnc00zja1lwi3yjmtyzllztrlngixm2vk.bin (C:\\Users\\). Unfortunately, we could not\r\nretrieve the file for analysis.\r\ns5.ps1, son.ps1 (AppData\\Local) - PowerShell SOCKS proxy script that connects to the C2 server\r\n91.92.136[.]20 over port 4001.\r\nFigure 3: Snippet of s5.ps1 script\r\nThe persistence via Registry Run Keys was created to run the PowerShell SOCKS proxy script with the following\r\nvalues:\r\nRegistry Run Key name: socks_powershell\r\nData (command to run): Powershell.exe -windowstyle hidden -ExecutionPolicy Bypass -File\r\n\"C:\\Users\\\\AppData\\Local\\s5.ps1\"\r\nThe threat actor(s) removed most of the files they dropped on the host including the results produced by\r\nBloodHound as well as an unidentified krb.txt file dropped under C:\\Users\\.\r\nAfter running BloodHound, the threat actor(s) attempted to move laterally by using PsExec to execute file rz.ps1\r\non a second host. This was not successful due to the PowerShell execution policy preventing execution of\r\nuntrusted scripts. We were unable to retrieve the rz.ps1 script, but we assess it was likely a Cobalt Strike payload.\r\nHow did we find it?\r\nBlueSteel, our machine-learning powered PowerShell classifier identified post-compromise activity on the\r\nsystem.\r\nWhat did we do?\r\nOur team of 24/7 SOC Cyber Analysts isolated the host and alerted the customer.\r\nThe SOC updated the customer with detailed findings and recommendations to remediate this threat.\r\nWe added C2 addresses to our global blocklist and performed proactive threat hunts for similar activity\r\nacross all customers.\r\nhttps://www.esentire.com/blog/gootloader-leads-to-cobalt-strike-and-hand-on-keyboard-activity\r\nPage 3 of 8\n\nWe also updated our Gootloader detection and runbook for this new infection technique.\r\nWhat can you learn from this TRU positive?\r\nGootloader is a prevalent drive-by threat distributed through poisoned search results. Infected devices\r\npresent a valuable foothold for adversaries to conduct follow-on attacks across the network.\r\nIn the above case, the infected device transitioned to a hands-on-keyboard attack in approximately 2\r\nhours.\r\nThe drive-by distribution method presents an alternative to email as a vector for delivering malicious code.\r\nGootloader uses blackhat SEO techniques to manipulate search results and deliver malware\r\ndisguised as documents.\r\nOther drive-by threats utilize malicious search engine advertisements to push lookalike software\r\ncontaining malware.\r\nGootloader follows a general trend observed across several threats where widely distributed, opportunistic\r\ninfections are weaponized for network intrusions including ransomware deployment.\r\nIn this case, we assess the goal was likely data theft or ransomware deployment. Gootloader has been\r\npreviously used as a precursor to the REvil ransomware group in 2021.\r\nRecommendations from our Threat Response Unit (TRU) Team:\r\nUsing Phishing and Security Awareness Training (PSAT), educate your employees regarding the risk of\r\nGootloader and, more broadly, the cybersecurity risks associated with using search engines to find free\r\ndocument templates.\r\nMake sure you trust document sources. Even legitimate Word and Excel documents from the\r\nInternet can lead to malware infections.\r\nEnsure your downloaded content is what you intended. If you intended to download a document\r\n(.docx) but you are served a JavaScript (.js) file, do not open it. Escalate it to your internal IT\r\nsecurity team.\r\nEnsure standard procedures are in place for employees to submit potentially malicious content for review.\r\nUse Windows Attack Surface Reduction rules to block JScript and VBScript from launching downloaded\r\ncontent.\r\nEmploy an Endpoint Detection and Response (EDR) product to help detect, isolate, and remediate cyber\r\nthreats impacting your company’s endpoint devices.\r\nIndicators of Compromise\r\nIndicator Note\r\n23d3d8cd3a5b8e4703a9b91970d790d1 zieu.ps1 (Cobalt Strike payload)\r\n785fcb9380b4c2310c2200790641bc73 s5.ps1 (PowerShell SOCKS proxy)\r\ncadb91ac90f52e27c0acae43b79aa202 son.ps1 (PowerShell SOCKS proxy)\r\nhttps://www.esentire.com/blog/gootloader-leads-to-cobalt-strike-and-hand-on-keyboard-activity\r\nPage 4 of 8\n\nbbbfab2763b717178141f0561584d087 contract salary calculator ontario 34123.js\r\nhxxps[://]skymedia360[.]com/xmlrpc[.]php Contacted domain\r\nhxxps[://]filorga[.]com/xmlrpc[.]php Contacted domain\r\nhxxp[://]breadoflifetabernacle[.]com/xmlrpc[.]php Contacted domain\r\nhxxps[://]lyngsfjord[.]com/xmlrpc[.]php Contacted domain\r\nhxxps[://]galonivan[.]com[.]br/xmlrpc[.]php Contacted domain\r\nhxxps[://]assistironline[.]net/xmlrpc[.]php Contacted domain\r\nhxxps[://]dexacoin[.]net/xmlrpc[.]php Contacted domain\r\nhxxps[://]thetripgoeson[.]com/xmlrpc[.]php Contacted domain\r\nhxxps[://]hcss[.]nl/xmlrpc[.]php Contacted domain\r\nhxxp[://]beechdesigngroup[.]com/xmlrpc[.]php Contacted domain\r\nhxxp[://]dentalofficeathens[.]gr/xmlrpc[.]php Contacted domain\r\nhxxp[://]aracelicolin[.]org[.]mx/xmlrpc[.]php Contacted domain\r\nhxxps[://]shareddata[.]org/xmlrpc[.]php Contacted domain\r\nhxxps[://]dunkandjump[.]com/xmlrpc[.]php Contacted domain\r\nhxxps[://]nickthomm[.]com/xmlrpc[.]php Contacted domain\r\nhxxps[://]1worldsync[.]com/xmlrpc[.]php Contacted domain\r\nhxxps[://]hozoboz[.]com/xmlrpc[.]php Contacted domain\r\nhxxps[://]burmancoffee[.]com/xmlrpc[.]php Contacted domain\r\nhxxps[://]tonyevers[.]com/xmlrpc[.]php Contacted domain\r\nhxxps[://]serialowy[.]pl/xmlrpc[.]php Contacted domain\r\neSentire’s Threat Response Unit (TRU) is a world-class team of threat researchers who develop new detections\r\nenriched by original threat intelligence and leverage new machine learning models that correlate multi-signal data\r\nand automate rapid response to advanced threats.\r\nIf you are not currently engaged with an MDR provider, eSentire MDR can help you reclaim the advantage and\r\nput your business ahead of disruption.\r\nLearn what it means to have an elite team of Threat Hunters and Researchers that works for you. Connect with an\r\neSentire Security Specialist.\r\nhttps://www.esentire.com/blog/gootloader-leads-to-cobalt-strike-and-hand-on-keyboard-activity\r\nPage 5 of 8\n\nTo learn how your organization can build cyber resilience and prevent business disruption with eSentire’s Next\r\nLevel MDR, connect with an eSentire Security Specialist now.\r\nGET STARTED\r\nABOUT ESENTIRE’S THREAT RESPONSE UNIT (TRU)\r\nThe eSentire Threat Response Unit (TRU) is an industry-leading threat research team committed to helping your\r\norganization become more resilient. TRU is an elite team of threat hunters and researchers that supports our 24/7\r\nSecurity Operations Centers (SOCs), builds threat detection models across the eSentire XDR Cloud Platform, and\r\nworks as an extension of your security team to continuously improve our Managed Detection and Response\r\nservice. By providing complete visibility across your attack surface and performing global threat sweeps and\r\nhttps://www.esentire.com/blog/gootloader-leads-to-cobalt-strike-and-hand-on-keyboard-activity\r\nPage 6 of 8\n\nproactive hypothesis-driven threat hunts augmented by original threat research, we are laser-focused on defending\r\nyour organization against known and unknown threats.\r\n Back to blog\r\nTake Your Cybersecurity Program to the Next Level with eSentire MDR.\r\nBUILD A QUOTE\r\nin this blog\r\nhttps://www.esentire.com/blog/gootloader-leads-to-cobalt-strike-and-hand-on-keyboard-activity\r\nPage 7 of 8\n\nWhat did we find?How did we find it?What did we do?What can you learn from this TRU positive?\r\nRecommendations from our Threat Response Unit (TRU) Team:\r\nSource: https://www.esentire.com/blog/gootloader-leads-to-cobalt-strike-and-hand-on-keyboard-activity\r\nhttps://www.esentire.com/blog/gootloader-leads-to-cobalt-strike-and-hand-on-keyboard-activity\r\nPage 8 of 8",
	"extraction_quality": 1,
	"language": "EN",
	"sources": [
		"Malpedia"
	],
	"references": [
		"https://www.esentire.com/blog/gootloader-leads-to-cobalt-strike-and-hand-on-keyboard-activity"
	],
	"report_names": [
		"gootloader-leads-to-cobalt-strike-and-hand-on-keyboard-activity"
	],
	"threat_actors": [
		{
			"id": "610a7295-3139-4f34-8cec-b3da40add480",
			"created_at": "2023-01-06T13:46:38.608142Z",
			"updated_at": "2026-04-10T02:00:03.03764Z",
			"deleted_at": null,
			"main_name": "Cobalt",
			"aliases": [
				"Cobalt Group",
				"Cobalt Gang",
				"GOLD KINGSWOOD",
				"COBALT SPIDER",
				"G0080",
				"Mule Libra"
			],
			"source_name": "MISPGALAXY:Cobalt",
			"tools": [],
			"source_id": "MISPGALAXY",
			"reports": null
		}
	],
	"ts_created_at": 1775439064,
	"ts_updated_at": 1775791463,
	"ts_creation_date": 0,
	"ts_modification_date": 0,
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