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

Static analysis result for SHA-256 df0204fb52f77e7d…

MALICIOUS

Office (OOXML)

537.3 KB Created: 2018-12-07 23:27:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-04-06
MD5: 37c8c85e6beaeb416af21ff908c74ba3 SHA-1: 8a7af803ccd9aa89ef3466a904a69eab9c5f2848 SHA-256: df0204fb52f77e7d2fad29551c3eb3d34c805df0f1a9a90ead092d642422f4a2
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.Dropper.Remcos-6956144-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Dropper.Remcos-6956144-0
  • 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 747520 bytes
SHA-256: 95f80649927a67b359ffffc997ec0433f60545039162887a3ad20a85c5aa3e7e
Detection
ClamAV: Win.Dropper.Remcos-6956144-0
Obfuscation or payload: unlikely
ooxml_oleobject_00_ole10native_00.bin ole-package OOXML word/embeddings/oleObject1.bin Ole10Native stream: Ole10Native 739288 bytes
SHA-256: c33bd8a72fad74d11c2572c9e044ca139b6eeaa47be6cffa24d7d218814b8af2
Detection
ClamAV: Win.Dropper.Remcos-6956144-0
Obfuscation or payload: unlikely
emf_00.emf ooxml-emf OOXML EMF part: word/media/image1.emf 7424 bytes
SHA-256: 6d38810e26beada9164060c0da3c7ce22b0f82eceb157b42c3bb01cd14fccea0