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

Static analysis result for SHA-256 a3e56a01d2e607d3…

MALICIOUS

Office (OOXML) / .XLSX

705.3 KB Created: 2023-07-26 19:45:53 UTC Authoring application: Microsoft Excel 12.0000 First seen: 2023-08-28
MD5: 964afd092d10290fd808713e07b5f832 SHA-1: eedf8ccc846b080b014bd0fc5181b945cbbba20a SHA-256: a3e56a01d2e607d3c5e05fab78279f46fd2066cbe4e598b33c2de6e8cd58ff53
100 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious File

The sample is an OOXML 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 like CVE-2017-11882. This technique is commonly used to deliver a second-stage malicious payload.

Heuristics 3

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/vrpU.yUh4 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
d6b8efb9a0b6156571c006395dd1deb411368f40a3e414ab0312be440aff6242		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/vrpU.yUh4 1004544 bytes
ooxml_oleobject_00_ole10native_00.bin
d03d8f5aa20601b487aaf8c4c714c4f2cc9f90e437a1f57a731b847ad07c92f2		 ole-package OOXML xl/embeddings/vrpU.yUh4 Ole10Native stream: oLe10NatIvE 993800 bytes

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