Win.Dropper.Remcos-6956144-0 — Office (OOXML) malware analysis

Static analysis result for SHA-256 94a8bcb550f67825…

MALICIOUS

Office (OOXML)

545.0 KB Created: 2018-12-13 13:54:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2019-11-20
MD5: 8cb777370f34a39c9ca3d3a0c53d1867 SHA-1: 12c72b81054b8ee23be8a0d9f71f60b856fc852f SHA-256: 94a8bcb550f67825f3e0fe3069b37cd6fbf4601a2b34d083913bc8f66b9ae60f
244 Risk Score

Malware Insights

Win.Dropper.Remcos-6956144-0 · confidence 95%

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a malicious OOXML document that contains an embedded OLE object. This object, identified as a risky file type, likely exploits CVE-2026-21514 to drop and execute a payload. ClamAV detections confirm the presence of Win.Dropper.Remcos-6956144-0, indicating a dropper functionality designed to download further malicious content from the identified URLs.

Heuristics 6

  • OOXML Ole10Native with payload/link indicators — possible CVE-2026-21514 high CVE likely CVE_2026_21514
    Office document contains embedded OLE (word/embeddings/oleObject1.bin) with Ole10Native plus executable, PE, or risky remote-link indicators. This is a likely CVE-2026-21514 exploitation shape.
  • ClamAV: Win.Trojan.Gamarue-6974517-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Gamarue-6974517-0
  • Ole10Native package drops an auto-executable payload critical OFFICE_PACKAGE_RISKY_FILE
    OLE Package displayName or fullPath ends in a directly auto-executable extension (a runnable binary or a script the default shell host runs on double-click). Embedding such a payload inside an Office document has no benign authoring use — it is a malware-delivery dropper.
  • Embedded OLE object medium OOXML_OLE_OBJECT
    Document contains an embedded OLE object
  • Payload URL recovered from embedded OLE object (8 URLs) info OOXML_EMBEDDED_OBJECT_URL
    An embedded OLE object (xl/word/ppt embeddings) carries a next-stage download URL in its Ole10Native/Package stream — stored literally (incl. UTF-16) or base64-encoded — which the package-level URL sweep does not see. Surfaced as an IOC; self-validating (only real payload hosts).
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://s.symcd.com06 In document text (OOXML body / shared strings)
    • http://ts-ocsp.ws.symantec.com0In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvasIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2014/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/inkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2017/model3dIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2012/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2016/wordml/cidIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2015/wordml/symexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn document text (OOXML body / shared strings)
    • https://d.symcb.com/cps0%In document text (OOXML body / shared strings)
    • https://d.symcb.com/rpa0In document text (OOXML body / shared strings)
    • http://s.symcb.com/universal-root.crl0In document text (OOXML body / shared strings)
    • https://d.symcb.com/rpa0@In document text (OOXML body / shared strings)
    • http://ts-crl.ws.symantec.com/sha256-tss-ca.crl0In document text (OOXML body / shared strings)
    • http://ts-aia.ws.symantec.com/sha256-tss-ca.cer0In document text (OOXML body / shared strings)
    • http://ts-aia.ws.symantec.com/sha256-tss-ca.cer0(In document text (OOXML body / shared strings)

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
ooxml_oleobject_00.bin ooxml-ole-object OOXML embedded OLE part: word/embeddings/oleObject1.bin 805376 bytes
SHA-256: 1e9542718420d26267f391442ab5fd2a463452f7b352cd10ef2616a6398989e8
Detection
ClamAV: Win.Trojan.Gamarue-6974517-0
Obfuscation or payload: unlikely
ooxml_oleobject_00_ole10native_00.bin ole-package OOXML word/embeddings/oleObject1.bin Ole10Native stream: Ole10Native 796612 bytes
SHA-256: 26f6a64bc2f490f35e623590387c1e8e4a5ed2afafab68716f1d558c4543d62f
Detection
ClamAV: Win.Trojan.Gamarue-6974517-0
Obfuscation or payload: unlikely
emf_00.emf ooxml-emf OOXML EMF part: word/media/image1.emf 7440 bytes
SHA-256: 25754ecfae9f2a858b6f75ede024a272b4a0235bc36d7b4de9f70f48d44a645e