Office (OOXML) / .XLSX malware analysis — malicious · 7a8c9f4488321586

MALICIOUS

Office (OOXML) / .XLSX

1.82 MB Created: 2023-08-03 11:34:29 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2023-08-10

MD5: 4181ffcd9f52664e1799ecd17be0ecf1 SHA-1: 345c99a845946147d4476580a5dae1bb163047d1 SHA-256: 7a8c9f448832158625b81208cd8b4b573d233d6c9c8b36759115662aa5de67a1

142 Risk Score

Malware Insights

MITRE ATT&CK

T1203 Exploitation for Client Execution T1559.001 Component Object Model

The file is an Excel document containing an embedded OLE object, specifically identified as a vulnerable Equation Editor object. Heuristics indicate exploitation of CVE-2018-0798, suggesting the Equation Editor is used to execute a malicious payload. The embedded object's structure and high entropy are anomalous, pointing towards a packed or obfuscated second-stage artifact.

Heuristics 5

Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR

Embedded OLE object xl/embeddings/yvaUtC.M0s 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` `9383bafe4e97e90e3b778bdbf4503156f235be8d7c04b3d92f30efe1b87de74c`	ooxml-ole-object	OOXML embedded OLE part: xl/embeddings/yvaUtC.M0s	2177536 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact entropy is 7.98, consistent with packed or encrypted content.
`ooxml_oleobject_00_ole10native_00.bin` `51b52938d6d95509084b15b23d124fd954cb9f845faef698d0a4ac7d31423411`	ole-package	OOXML xl/embeddings/yvaUtC.M0s Ole10Native stream: ole10NATIvE	2157952 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.