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

Static analysis result for SHA-256 ac826a5d18b94967…

MALICIOUS

Office (OOXML) / .XLSX

714.6 KB Created: 2023-08-03 11:34:29 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2023-08-28
MD5: d0521b06b473492250a94279f1179a2f SHA-1: 78e5f17c4ee0c8a5bf845daf90e7ad52cae31f52 SHA-256: ac826a5d18b94967786544d631f253b7e9a8c18d5784d94fd5f73d34db8067cf
100 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.001 Malicious Link

The sample is an Office document 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 a significantly larger declared inner size than the actual stream size, strongly suggesting exploitation of a vulnerability like CVE-2017-11882. This technique is commonly used to download and execute a second-stage payload.

Heuristics 3

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/Z2Rp1j.JKuyG7n 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
7c34ad2f3ad167272af4c406ed88e16db2573b536ebaa81f37dadea352686561		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/Z2Rp1j.JKuyG7n 1032704 bytes
ooxml_oleobject_00_ole10native_00.bin
9b1d273ef832609c78cf04c103556db5f934b70d40d6c4b8ad6cde5435f853b8		 ole-package OOXML xl/embeddings/Z2Rp1j.JKuyG7n Ole10Native stream: OlE10nATIvE 1022189 bytes

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