Office (OOXML) / .XLSX malware analysis — malicious · b766946cb0afabdf

MALICIOUS

Office (OOXML) / .XLSX

1.32 MB Created: 2022-11-18 02:05:27 UTC Authoring application: Microsoft Excel 12.0000

MD5: 3bfb7572c7c7954243b8a32f364e4a80 SHA-1: 8e7c917372338e8ce32cdc3b177afe38a3570fc3 SHA-256: b766946cb0afabdf07a8710c4a25db89f55043059f655d826afe4f98cb4d9b58

142 Risk Score

Malware Insights

MITRE ATT&CK

T1566.002 Spearphishing Attachment T1204.002 Malicious File

The file is an Excel spreadsheet containing an embedded OLE object, specifically a malicious Equation Editor object. Heuristics indicate exploitation of CVE-2018-0798, a vulnerability in the Equation Editor component, which is likely used to execute a second-stage payload. The high entropy and anomalous stream sizes within the embedded object suggest it contains obfuscated malicious code.

Heuristics 5

Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR

Embedded OLE object xl/embeddings/LR.iFIL 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` `a27409aaa6dda828d7c3ed52a82aadccf3067763c06b6835e1b1d952b59f5d6c`	ooxml-ole-object	OOXML embedded OLE part: xl/embeddings/LR.iFIL	1668096 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact entropy is 7.99, consistent with packed or encrypted content.
`ooxml_oleobject_00_ole10native_00.bin` `f3b9b7afcaead08ff8406b844fe3e3c5092c37f1d37f41bfec1523d62e6c19e0`	ole-package	OOXML xl/embeddings/LR.iFIL Ole10Native stream: OlE10nAtiVE	1652443 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.