Malicious Office (OOXML) / .XLSX — malware analysis report

Static analysis result for SHA-256 26e3290a32d6cc72…

MALICIOUS

Office (OOXML) / .XLSX

748.3 KB Created: 2023-08-03 11:34:29 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2023-08-09
MD5: c546968a1f13d20f92a1966891f84ad8 SHA-1: 1f881d603737744ee6ea33a501495540d32b450e SHA-256: 26e3290a32d6cc723113c8e0a9c4b79297c60f545e4b18b5ec905718fe940fb8
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1559 Component Object Model Hijacking

The sample is an Office document containing an embedded OLE object, specifically an Equation Editor object. High-severity heuristics indicate that this Equation Editor object is anomalous and carries a payload, strongly suggesting exploitation of CVE-2018-0798. This technique is commonly used to deliver second-stage malware.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/CV7yj8wbk.Kssetj 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
ooxml_oleobject_00.bin
7c8cd908a2415996ceb40e518159af1f13e9adbdf3a60be2ff3aabf045e2fb4e		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/CV7yj8wbk.Kssetj 1053184 bytes
ooxml_oleobject_00_ole10native_00.bin
319f4f2fd96111ec9bad3363156f24323d0dfbba59e901bbbe75e2e44150b244		 ole-package OOXML xl/embeddings/CV7yj8wbk.Kssetj Ole10Native stream: OLe10nATiVe 1042212 bytes

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