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

Static analysis result for SHA-256 3b1a9c9358e4e0a6…

MALICIOUS

Office (OOXML) / .XLSX

596.5 KB Created: 2023-08-03 11:34:29 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2023-09-20
MD5: 8cd14d38da24b08fd6fbba6c49120146 SHA-1: a1022f005018e73eee75ecaac209c1ab6f488763 SHA-256: 3b1a9c9358e4e0a6106b1176634969d6e3372cfa1e8956bee66ea90c02e2b65d
100 Risk Score

Malware Insights

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

The sample is an Excel file containing an embedded OLE object, specifically identified as a Microsoft Equation Editor object. High-severity heuristics indicate that this Equation Editor object carries a payload-like Ole10Native stream with an anomalous header and size discrepancy, strongly suggesting exploitation of a vulnerability within the Equation Editor component. This is a common technique for delivering second-stage malware.

Heuristics 3

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/MH.z1 contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
  • 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
9e2e98542e88f18d298296899f8ed11c04ef0cf227a2b4a847a6c1cd955a8bbf		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/MH.z1 829952 bytes
ooxml_oleobject_00_ole10native_00.bin
0a1861bef04df9bc245a46aeb931b3b0008f80ba1ba64e241b2ed67d81c784e0		 ole-package OOXML xl/embeddings/MH.z1 Ole10Native stream: OLe10NAtIVe 821053 bytes

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