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

Static analysis result for SHA-256 4676d10538be8fe4…

MALICIOUS

Office (OOXML) / .XLSX

631.8 KB Created: 2023-09-19 06:25:18 UTC Authoring application: Microsoft Excel 12.0000 First seen: 2023-10-05
MD5: a70f8a4508db3e2efc6e99dcd4c28a0d SHA-1: be384db802b037fecf340ef306558c2628ea86b8 SHA-256: 4676d10538be8fe472991f13c06f7a3131856fdd16f4cdfeee86a46076159f2e
100 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.001 Malicious Link

The XLSX file contains an embedded OLE object, specifically identified as a Equation Editor object. High-severity heuristics indicate that this Equation Editor object carries a payload-like Ole10Native stream with an anomalous size difference, strongly suggesting exploitation of a known vulnerability like CVE-2017-11882. This technique is commonly used to download and execute a second-stage payload.

Heuristics 3

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/NlFt.eT contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
  • 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
ea8db7745dbaeade2a3ad5d67f715ee5ac6d08a7dd477e211cc4ed409c0905c3		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/NlFt.eT 862720 bytes
ooxml_oleobject_00_ole10native_00.bin
5da3e42951f0c1f2b16b31a6a2e04df941a147130448ce23f1b93f45bd896c25		 ole-package OOXML xl/embeddings/NlFt.eT Ole10Native stream: oLe10NATivE 853032 bytes

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