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

Static analysis result for SHA-256 25ac56fa9637967a…

MALICIOUS

Office (OOXML) / .XLSX

744.3 KB Created: 2021-09-22 12:07:42 UTC Authoring application: Microsoft Excel 12.0000 First seen: 2021-09-29
MD5: 51cfc4755260459f4417f9ed5c85b0e3 SHA-1: 99c2b3e99f6e811cd5d5dbff713b5cb5f190a93a SHA-256: 25ac56fa9637967ae898c22748283b3655c5dcb00f3c9100d6e787b45e9e4714
140 Risk Score

Malware Insights

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

The sample is an Excel file containing an embedded OLE object, specifically identified as a vulnerable Equation Editor object. High-severity heuristics indicate exploitation of CVE-2018-0798, suggesting the embedded object is designed to deliver a malicious payload. The embedded OLE object's native stream exhibits anomalies consistent with exploit delivery.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/jai9e5a.zdVORZ3 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
d0b5e1714ab8fc6fa9122371808a81d4f5abb50aa10e69f67d622223f6f25cef		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/jai9e5a.zdVORZ3 963072 bytes
ooxml_oleobject_00_ole10native_00.bin
6eae5903134837d6da0295ed05ba383d65ac64b46abbef43f01d1513a352b33f		 ole-package OOXML xl/embeddings/jai9e5a.zdVORZ3 Ole10Native stream: olE10naTIVe 953257 bytes

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