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

Static analysis result for SHA-256 6733ad71b1efaa05…

MALICIOUS

Office (OOXML) / .XLSX

820.8 KB Created: 2021-01-13 03:25:40 UTC Authoring application: Microsoft Excel 12.0000
MD5: a7abd2226a16aaa38f30ef70017c55c8 SHA-1: ac997bd76735b7ea41daeb330057ef6c3f7de1a3 SHA-256: 6733ad71b1efaa05a8b38003fa18b5ba5a8bab8a04b31d1dfe461619791a8b7e
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an Excel file containing an embedded OLE object, specifically identified as a vulnerable Equation Editor object. High-severity heuristics indicate exploitation of CVE-2018-0798 via an anomalous Equation Editor native stream, suggesting it's designed to execute a payload. The embedded OLE object's path is noted as a potential indicator.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/oq.NQyfM 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
7f41e28d6cddebd4b203c02ee3df98f65d38f1fab8e40c5aa9ca7ea819969428		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oq.NQyfM 1131008 bytes
ooxml_oleobject_00_ole10native_00.bin
faaaa377f8ac18d7dbf146e70ea6272eacc41ea9b24d214e0de4553fcb4ac1bc		 ole-package OOXML xl/embeddings/oq.NQyfM Ole10Native stream: OLe10natIve 1119323 bytes

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