{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/office-addins/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[],"_cs_exploited":false,"_cs_products":["Microsoft Office","Microsoft Defender XDR","Elastic Defend","SentinelOne Cloud Funnel","LogiOptions","Sidekick.vsto"],"_cs_severities":["medium"],"_cs_tags":["office-addins","phishing","initial-access"],"_cs_type":"advisory","_cs_vendors":["Microsoft","Logitech","Elastic","SentinelOne"],"content_html":"\u003cp\u003eAttackers are increasingly leveraging malicious Microsoft Office Add-Ins to gain initial access and persistence on victim systems. These add-ins, often delivered through phishing campaigns, contain embedded malicious code. This detection identifies unusual execution patterns, such as Office applications (WINWORD.EXE, EXCEL.EXE, POWERPNT.EXE, MSACCESS.EXE, VSTOInstaller.exe) launching add-ins (wll, xll, ppa, ppam, xla, xlam, vsto) from suspicious paths like Temp or Downloads directories, or with atypical parent processes (explorer.exe, OpenWith.exe, cmd.exe, powershell.exe). The detection logic filters out known benign activities to minimize false positives, focusing on anomalies indicative of malicious intent, such as installations of Logitech software. This activity matters because successful exploitation can lead to arbitrary code execution, data theft, and further compromise of the victim\u0026rsquo;s network.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eA user receives a phishing email containing a malicious Microsoft Office document.\u003c/li\u003e\n\u003cli\u003eThe user opens the document, which prompts them to enable macros or install an add-in.\u003c/li\u003e\n\u003cli\u003eThe malicious add-in (wll, xll, ppa, ppam, xla, xlam, vsto) is downloaded from a remote server or dropped into a suspicious directory, such as %TEMP% or %APPDATA%.\u003c/li\u003e\n\u003cli\u003eThe user executes an Office application (WINWORD.EXE, EXCEL.EXE, POWERPNT.EXE, MSACCESS.EXE), which loads the malicious add-in.\u003c/li\u003e\n\u003cli\u003eThe malicious add-in executes arbitrary code, potentially downloading and executing a second-stage payload.\u003c/li\u003e\n\u003cli\u003eThe add-in may establish persistence by modifying registry keys or creating scheduled tasks.\u003c/li\u003e\n\u003cli\u003eThe attacker gains initial access to the system and can perform reconnaissance, lateral movement, and data exfiltration.\u003c/li\u003e\n\u003cli\u003eThe attacker achieves their objective, which could include data theft, ransomware deployment, or intellectual property theft.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eA successful attack can lead to complete system compromise, data theft, and potential ransomware deployment. Organizations across all sectors are at risk, particularly those with a high volume of email traffic. The use of malicious Office Add-Ins provides attackers with a persistent foothold within the victim\u0026rsquo;s environment, allowing for long-term data collection and disruption of business operations. This can lead to significant financial losses, reputational damage, and legal liabilities.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eOffice Add-In Loaded From Suspicious Path\u003c/code\u003e to detect add-ins loaded from temporary or download directories based on \u003ccode\u003eprocess.args\u003c/code\u003e and \u003ccode\u003eprocess.name\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eOffice Add-In Loaded By Suspicious Parent\u003c/code\u003e to detect add-ins loaded by \u003ccode\u003ecmd.exe\u003c/code\u003e or \u003ccode\u003epowershell.exe\u003c/code\u003e based on \u003ccode\u003eprocess.parent.name\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eInvestigate any instances of \u003ccode\u003eVSTOInstaller.exe\u003c/code\u003e executing with the \u003ccode\u003e/Uninstall\u003c/code\u003e argument, as this may indicate suspicious activity, correlating with the exclusion rule in the provided query.\u003c/li\u003e\n\u003cli\u003eMonitor for Office applications launching add-ins with parent processes of \u003ccode\u003eexplorer.exe\u003c/code\u003e or \u003ccode\u003eOpenWith.exe\u003c/code\u003e using process creation logs and the provided query logic.\u003c/li\u003e\n\u003cli\u003eImplement stricter email filtering to prevent phishing emails containing malicious Office documents from reaching end-users.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-03T14:00:00Z","date_published":"2024-01-03T14:00:00Z","id":"/briefs/2024-01-office-addins/","summary":"This rule detects suspicious execution of Microsoft Office applications launching Office Add-Ins from unusual paths or with atypical parent processes, potentially indicating an attempt to gain initial access via a malicious phishing campaign.","title":"Suspicious Execution via Microsoft Office Add-Ins","url":"https://feed.craftedsignal.io/briefs/2024-01-office-addins/"}],"language":"en","title":"CraftedSignal Threat Feed — Office-Addins","version":"https://jsonfeed.org/version/1.1"}