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

Static analysis result for SHA-256 c849bf87496b531f…

MALICIOUS

Office (OOXML) / .XLSX

632.2 KB Created: 2023-09-27 08:05:40 UTC Authoring application: Microsoft Excel 12.0000 First seen: 2023-09-29
MD5: a019f6af8b4da63fe9000b04db50cde1 SHA-1: 2d672f3c154ce30866a6e414c1265bc4ae9cff3e SHA-256: c849bf87496b531fd9ca887e961def730f9c9fc241c61e9977e11c76ed40ea72
100 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, identified as an 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. This technique is commonly used to deliver second-stage malware.

Heuristics 3

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/p98QL.XTc29 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
f96a84cddc090e1cfce31095f3b26b4e968b774f865784a4a33a508fbf40ef5b		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/p98QL.XTc29 896000 bytes
ooxml_oleobject_00_ole10native_00.bin
49c1ea940c5c74be5ab732d63bf1d1787d02ee0a5914dc412d63203b0665caae		 ole-package OOXML xl/embeddings/p98QL.XTc29 Ole10Native stream: olE10natIve 886716 bytes

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