Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 128fc35697b7e893…

MALICIOUS

Office (OOXML)

610.8 KB Created: 2013-01-29 00:41:00 UTC Authoring application: Microsoft Office Word 14.0000 First seen: 2015-09-18
MD5: 25631c7360f0603841daee30c5b5ee50 SHA-1: ca44f250c97e2a522a2cf045d4cf43db3c8921f9 SHA-256: 128fc35697b7e893870f96fe537553436c8f363723eb8b21aeb1baa15a2b529d
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1105 Ingress Tool Transfer

The sample contains an embedded OLE object that functions as a script dropper. This script is designed to download and execute a payload, disguised as 'AdobeReader.exe', from a list of URLs. The document body suggests a lure to save the document for compatibility, which is a common social engineering tactic. The embedded script's behavior of fetching and executing a file strongly indicates a downloader or droppper functionality.

Heuristics 6

  • Ole10Native package payload is a download-and-execute script critical OFFICE_PACKAGE_SCRIPT_DROPPER
    The OLE Package's embedded payload contains a script that hosts a shell (PowerShell/WScript/mshta), fetches a remote resource, and executes it — a download-and-run dropper. Embedding such a script inside an Office document via the Object Packager is a direct user-execution delivery technique (MITRE T1204.002), not a benign attachment.
  • 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 (5 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).
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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://ocsp.thawte.com0 Embedded OLE package script
    • http://ts-ocsp.ws.symantec.com07Embedded OLE package script
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvasIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In 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/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)
    • http://crl.thawte.com/ThawteTimestampingCA.crl0Embedded OLE package script
    • http://ts-aia.ws.symantec.com/tss-ca-g2.cer0Embedded OLE package script
    • http://ts-crl.ws.symantec.com/tss-ca-g2.crl0Embedded OLE package script
    • http://ts-crl.ws.symantec.com/tss-ca-g2.crl0(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 515584 bytes
SHA-256: 6a7b6ef338a8c4074bd90c2763f995cad5e36a5b60c4677e91836bcf508ba029
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.80, consistent with packed or encrypted content.
ooxml_oleobject_00_ole10native_00.bin ole-package OOXML word/embeddings/oleObject1.bin Ole10Native stream: Ole10Native 508931 bytes
SHA-256: 065b6a1bf961a70f51c1db5028801a1b16e1aafc09fb19d25754ddebac5dd608
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.83, consistent with packed or encrypted content.
emf_00.emf ooxml-emf OOXML EMF part: word/media/image1.emf 5112 bytes
SHA-256: 1129f456ff18dfe79aaa0fa2dc46172b983f5a4eb4d9f8c8de2bac2b9f85f4f2