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

Static analysis result for SHA-256 bedd39963a5f6036…

MALICIOUS

Office (OOXML) / .XLSX

2.78 MB Created: 2025-09-10 01:57:00 UTC Authoring application: Microsoft Excel 15.0300 First seen: 2026-01-12
MD5: 582ee420110c1d423c36376e6a7757a5 SHA-1: 0105db10c678d18e33511343a0de52b62a6bb88e SHA-256: bedd39963a5f6036c057172a7cf01751bfa1346ff5c3bc767612dfd252371182
100 Risk Score

Malware Insights

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

The XLSX file contains an embedded OLE object, specifically identified as a Equation Editor object. This object exhibits an anomaly where the Ole10Native stream is larger than expected, indicating it likely contains a malicious payload. This technique is commonly used to exploit vulnerabilities in the Equation Editor to execute arbitrary code.

Heuristics 3

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/jr.3urbxr 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
8817e4ee69b07c9e67e9d2def78deac3e7230a4d2b532bc01670aeb637a4ceba		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/jr.3urbxr 2806272 bytes
ooxml_oleobject_00_ole10native_00.bin
decf8016c6d1d26829d1833992a999aeb11b34fc3d928b80595f55b66aad0757		 ole-package OOXML xl/embeddings/jr.3urbxr Ole10Native stream: olE10natIVE 2782184 bytes

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