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

Static analysis result for SHA-256 d77c02b48bbe55ed…

MALICIOUS

Office (OOXML) / .XLSX

2.91 MB Created: 2025-09-10 01:57:00 UTC Authoring application: Microsoft Excel 15.0300 First seen: 2025-09-25
MD5: f4f0412f50b469281eae45bd8ef17f12 SHA-1: 2f1570d6fc3f8cd74d5b0fd2635c2c1a35c8bc9c SHA-256: d77c02b48bbe55ed3e1b83d3896062a99b6c65305f3834d9ad4b5ab13f637de3
100 Risk Score

Malware Insights

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

The sample is an Office Open XML spreadsheet 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, suggesting it's being used to exploit a known vulnerability. This pattern is commonly associated with the delivery of malicious payloads via weaponized documents.

Heuristics 3

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/0chywIS.Eta 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
4ca5b6af9b499094b73312b4253dc1bd56a50fd64a7d2af9976c8956f8d726f3		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/0chywIS.Eta 2976256 bytes
ooxml_oleobject_00_ole10native_00.bin
69fcbcf9396fef896c48beb585fa2c92960fc25442f91b0046e0f4abac4cdd69		 ole-package OOXML xl/embeddings/0chywIS.Eta Ole10Native stream: OLE10NaTive 2950154 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.