Office (OOXML) / .XLSX malware analysis — malicious · 73740b29628bb6dd

MALICIOUS

Office (OOXML) / .XLSX

2.84 MB Created: 2021-09-22 12:07:42 UTC Authoring application: Microsoft Excel 12.0000

MD5: 20d85a58d149014bace7f382a655c0b4 SHA-1: 481317a0960468df15ff162178a2a22cec59a21e SHA-256: 73740b29628bb6dd97ed2709fa708bfada26a5e50f6fa2da4d2aa51fecc1668f

142 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 Microsoft Equation Editor object. High-severity heuristics indicate that this object is anomalous and carries a payload, strongly suggesting exploitation of CVE-2018-0798. This technique is used to achieve client-side execution of a malicious payload.

Heuristics 5

Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR

Embedded OLE object xl/embeddings/aU.rl 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
Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE

One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 2

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`ooxml_oleobject_00.bin` `de44ee2de7bd47a394d43f6d0d9e488b0a05de22a0fe691f328f29b66178fa6f`	ooxml-ole-object	OOXML embedded OLE part: xl/embeddings/aU.rl	3299840 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact entropy is 7.96, consistent with packed or encrypted content.
`ooxml_oleobject_00_ole10native_00.bin` `9ed31aaaf897da9266f2c8baca3510b243113c0bd7145ea30db1f9d43c797322`	ole-package	OOXML xl/embeddings/aU.rl Ole10Native stream: Ole10Native	3271234 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact entropy is 7.99, consistent with packed or encrypted content.

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