{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","favicon":"https://feed.craftedsignal.io/favicon-32x32.png","feed_url":"https://feed.craftedsignal.io/products/microsoft-office-excel-word-powerpoint/feed.json","home_page_url":"https://feed.craftedsignal.io/","icon":"https://feed.craftedsignal.io/apple-touch-icon.png","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Microsoft Office (Excel, Word, PowerPoint)"],"_cs_severities":["high"],"_cs_tags":[],"_cs_type":"advisory","_cs_vendors":["Microsoft"],"content_html":"\u003cp\u003eResearch indicates that Microsoft Office applications can be abused to perform arbitrary file downloads from remote web servers. By exploiting unsanitized file validation routines within specific binaries, an attacker can trigger the download and execution of malicious payloads. This technique utilizes legitimate, signed binaries such as Winword.exe, Excel.exe, Powerpnt.exe, and Msoxmled.exe to initiate network requests to attacker-controlled infrastructure. These binaries are often trusted by security software, making them ideal candidates for living-off-the-land (LotL) attacks. Defenders should monitor for instances where these Office processes spawn network connections or execute command-line arguments containing HTTP or HTTPS URIs, as this behavior is typically indicative of malicious activity rather than standard document editing workflows.\u003c/p\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation allows attackers to pull secondary malicious payloads onto a target system, facilitating initial access, persistence, or data exfiltration. This technique has been observed in various contexts to bypass perimeter defenses by using trusted Microsoft-signed binaries to conduct malicious network communication.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cp\u003ePrioritize the deployment of the provided Sigma rule to monitor for suspicious command-line patterns originating from Office applications.\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eEnable process creation logging (Event ID 1) via Sysmon or Windows Security logs to capture command-line arguments.\u003c/li\u003e\n\u003cli\u003eImplement monitoring for child processes spawned by Office applications that initiate network connections.\u003c/li\u003e\n\u003cli\u003eBaseline expected behavior for internal Office applications to identify and filter out legitimate update or cloud-sync activities.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-09-25T05:20:42Z","date_published":"2026-09-25T05:20:42Z","id":"https://feed.craftedsignal.io/briefs/2026-09-office-arbitrary-download/","summary":"Adversaries may abuse legitimate Microsoft Office binaries to initiate arbitrary file downloads from remote locations, bypassing security controls by leveraging trusted processes.","title":"Detection of Arbitrary File Downloads via Microsoft Office Binaries","url":"https://feed.craftedsignal.io/briefs/2026-09-office-arbitrary-download/"}],"language":"en","title":"CraftedSignal Threat Feed - Microsoft Office (Excel, Word, PowerPoint)","version":"https://jsonfeed.org/version/1.1"}