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

Static analysis result for SHA-256 7650eca1f4e1f775…

MALICIOUS

Office (OOXML) / .XLSX

633.8 KB Created: 2022-08-10 18:51:50 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2024-08-16
MD5: 809d716c9cf3f615d182dc72022767cf SHA-1: b9b1174d232f8c8f89873253d48096f10916d789 SHA-256: 7650eca1f4e1f775abe6eedd27cc3d5131f57c927fc59bb4681d3897d499dd3e
140 Risk Score

Malware Insights

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

The file is an Excel spreadsheet containing an embedded OLE object, specifically identified as a Microsoft Equation Editor object. High-severity heuristics indicate that this object is anomalous and carries a payload, strongly suggesting exploitation of CVE-2018-0798. The embedded object's structure and size anomalies point to it being used to deliver a secondary malicious payload.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/UF.bC5 contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
  • CVE-2018-0798 — anomalous Equation Editor native stream high CVE likely CVE_2018_0798_EQUATION_NATIVE_ANOMALY
    Embedded Equation Editor OLE data contains anomalous native stream bytes consistent with a CVE-2018-0798-style Equation Editor exploit. This is treated as likely CVE evidence because the Equation object is malformed and payload-like, but it does not match the exact public matrix-overflow byte signature.
  • 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
1d56f19fe32afaaf23069b5b0968e7b16478ea14789b176d50f2d5e9624b92cb		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/UF.bC5 851456 bytes
ooxml_oleobject_00_ole10native_00.bin
bdc16a68613e0441ed329443007763fa91d86cf168a693e8f3b492f4f1f218b3		 ole-package OOXML xl/embeddings/UF.bC5 Ole10Native stream: ole10NaTive 842283 bytes

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