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

Static analysis result for SHA-256 f21641048c363841…

MALICIOUS

Office (OOXML) / .XLSX

601.3 KB Created: 2023-07-26 19:45:53 UTC Authoring application: Microsoft Excel 12.0000 First seen: 2023-09-25
MD5: 4a5b8828c333d0747bbcf63811c835ba SHA-1: 7657e939e03d8d1c37d7e4073e1dbda352f4f66d SHA-256: f21641048c363841f9d62cca0c545acdb5c700ce9b11cbafba77bbba024f6e86
100 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model Hijacking T1204.002 Malicious File

The XLSX file contains an embedded OLE object, specifically identified as a Equation Editor object. This object exhibits an anomaly where the Ole10Native stream appears to carry a payload, indicated by a significantly larger declared inner size than the actual stream size. This strongly suggests the exploitation of a known vulnerability within the Equation Editor component to execute arbitrary code.

Heuristics 3

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/5AmKgziY.zPhKLK 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
6fdbb6bd16d68bd7b050cd4ab89df96389e1faf851ff3389dfb0248f8db7411d		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/5AmKgziY.zPhKLK 895488 bytes
ooxml_oleobject_00_ole10native_00.bin
4cb8f69373f61701db621e276397733827aa6aab524980cd3f1e5755fe8f3c4d		 ole-package OOXML xl/embeddings/5AmKgziY.zPhKLK Ole10Native stream: ole10naTIVe 885997 bytes

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