Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 2ee5ff2c238c79cc…

MALICIOUS

Office (OOXML)

148.3 KB Created: 2018-09-09 12:27:30 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2020-05-25
MD5: aa8f391072b6d756d5393177cdaae6c6 SHA-1: df98670f7a09b3a4b370a8d91f6031924df3034f SHA-256: 2ee5ff2c238c79cc89f9fe8eec031bbbc91ed21b52d43391cc789923cc07b662
162 Risk Score

Malware Insights

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

The sample is an OOXML file containing an embedded OLE object, specifically an Equation Editor object. Heuristics indicate this object exploits CVE-2018-0798 via an anomalous native stream, suggesting it's designed to deliver a payload. The document body contains a lure to 'ENABLE EDITING ABOVE FOR CLEARER VIEW OF IMAGE', which is a common tactic to bypass macro security and execute embedded exploits.

Heuristics 6

  • 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.
  • Equation Editor object carries payload-like Ole10Native stream high OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY
    Embedded OLE object declares the Equation Editor CLSID but stores a large high-entropy Ole10Native stream with malformed package sizing. This is an exploit-shaped Equation/OLE payload container seen in malicious OOXML samples. It is not assigned to a specific CVE unless the MTEF/Equation Native primitive also matches.
  • 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 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.

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 92160 bytes
SHA-256: 87bcb73b4a6228e21ca38897b17402124cf3dee4ed725986e682cad8a0f394bb
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.96, consistent with packed or encrypted content.
ooxml_oleobject_00_ole10native_00.bin ole-package OOXML xl/embeddings/oleObject1.bin Ole10Native stream: Ole10NATive 89014 bytes
SHA-256: 09f6c0a6e2e65fac36cf7a0c4802774f824b60d633fe2dafd965968527a654cb
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.