Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 f1bdedec6c339826…

MALICIOUS

Office (OOXML)

14.7 KB Created: 1996-10-14 23:33:28 UTC Authoring application: Microsoft Excel 15.0300 First seen: 2020-09-07
MD5: 35a26b8047b94c8b05c5c1470768afba SHA-1: 668a171e193819b25f0d2837713510ae4bff5492 SHA-256: f1bdedec6c33982685fb295d2cce69040a63b2dfcd6ec3e003d23d8077723c06
140 Risk Score

Malware Insights

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

The sample is an Office document containing an embedded OLE object, specifically an Equation Editor object. Heuristics indicate this object exploits CVE-2018-0798 and contains suspicious shellcode. The document also contains a lure to enable editing and macros, a common tactic for macro-based malware droppers. The embedded OLE object is the primary indicator of malicious activity, likely serving as a dropper for a second-stage payload.

Heuristics 5

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/oleObject1.bin contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
  • CVE-2018-0798 — anomalous Equation Editor native stream high CVE likely CVE_2018_0798_EQUATION_NATIVE_ANOMALY
    Embedded Equation Editor OLE data contains anomalous native stream bytes consistent with a CVE-2018-0798-style Equation Editor exploit. This is treated as likely CVE evidence because the Equation object is malformed and payload-like, but it does not match the exact public matrix-overflow byte signature.
  • Embedded OLE object medium OOXML_OLE_OBJECT
    Document contains an embedded OLE object
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • Suspicious extracted artifact medium 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.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
ooxml_oleobject_00.bin ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject1.bin 4096 bytes
SHA-256: 4eed1a24193150dd30bce0c729da09759aa314f152966b2ccecfbb6da65619f9
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis found candidate code region(s). Indicators: SC_GETPC_CALL
ooxml_oleobject_00_ole10native_00.bin ole-package OOXML xl/embeddings/oleObject1.bin Ole10Native stream: ole10nATIVE 1593 bytes
SHA-256: a31cfa75836c99d31c89cf9defa6ad1dd8b564de2b33782c1839dbbc0e693700
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis found candidate code region(s). Indicators: SC_GETPC_CALL