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

Static analysis result for SHA-256 ec0f998453e31255…

MALICIOUS

Office (OOXML) / .XLSX

896.1 KB Created: 2022-11-18 02:05:27 UTC Authoring application: Microsoft Excel 12.0000 First seen: 2023-05-04
MD5: 2e5428a15a37026ad74f3bf13f15ce40 SHA-1: f97238cfc6bf1c84ae8d69df7ca5461bb764460c SHA-256: ec0f998453e3125596d9907d4e5fdfc367ddee82239fadc50a7c67ed1cad4c64
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious File T1559 Component Object Model Hijacking T1559.001 Component Object Model Hijacking: Component Object Model Hijacking

The file contains an embedded OLE object, specifically an Equation Editor object, which exhibits anomalies indicative of CVE-2018-0798 exploitation. The object's Ole10Native stream has an impossible header and a declared inner size far exceeding the stream size, suggesting it carries a malicious payload. This exploit likely serves as a dropper for a secondary malicious component.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/WfdzqTGJU.nAvzx2 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
18ec02beefad015a881b2a7f254fd085f89b9a7d03dcd414b4a1998e11ef0207		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/WfdzqTGJU.nAvzx2 1229824 bytes
ooxml_oleobject_00_ole10native_00.bin
b773643014a5e83204f498d2305f5d773361adefc104f84c26a820c1d8f672c6		 ole-package OOXML xl/embeddings/WfdzqTGJU.nAvzx2 Ole10Native stream: Ole10naTiVE 1218006 bytes

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