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

Static analysis result for SHA-256 6af7fa6ca7b67173…

MALICIOUS

Office (OOXML) / .XLSX

861.2 KB Created: 2021-08-09 02:12:21 UTC Authoring application: Microsoft Excel 12.0000
MD5: 27910e41c08da5869b37b252706b2553 SHA-1: 3e6fd1b2b8f444c60ab159487c6ffb1e8589e30e SHA-256: 6af7fa6ca7b67173104136ffcd1fdd0f41c3336c7b958c51235be6c7406e3651
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample contains an embedded OLE object, specifically identified as a vulnerable Equation Editor component. High-severity heuristics indicate that this object is anomalous and carries a payload, strongly suggesting exploitation of CVE-2018-0798 for client execution. The presence of an embedded malicious object within an Office document points to a likely spearphishing attachment delivery method.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/dOoOLrpEH.sU 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
31a27dd9a29bcb39bcdbff5ed00fc843dcf308dc958195feaed604be97fa51aa		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/dOoOLrpEH.sU 1114624 bytes
ooxml_oleobject_00_ole10native_00.bin
52bd8127f6d03fde795f06c0b3ee707e4487e1bbf1b946f4fd8557080d13e1ad		 ole-package OOXML xl/embeddings/dOoOLrpEH.sU Ole10Native stream: OlE10nAtIVE 1103603 bytes

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