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

Static analysis result for SHA-256 1b4f3c59567b6044…

MALICIOUS

Office (OOXML) / .XLSX

751.7 KB Created: 2010-06-04 08:55:28 UTC Authoring application: Microsoft Excel 15.0300 First seen: 2023-09-08
MD5: 977500d68cdec61aac050e601c862be0 SHA-1: 890f65e718cd4fedec4a496126da88a7974c8547 SHA-256: 1b4f3c59567b604479ee95145fdb8d8782b0bbf808b148ac41f8d3628bb3d9b2
140 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model and Distributed Component Object Model: Component Object Model T1204.002 Malicious File: User Execution: Malicious File

The sample is an Excel document containing 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, strongly suggesting exploitation of a vulnerability like CVE-2017-11882. The NOP sled further supports the presence of executable code. The document body appears to be a fabricated invoice, likely a lure to encourage user interaction with the malicious embedded object.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/3sIYbfoXO.NKjW contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
  • NOP sled detected high SC_NOP_SLED
    Found 20+ consecutive 0x90 bytes
  • 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
f66ffb33e85a76c11877feceadde486f2614cf4da6ce4b8b678274cdbe02d27b		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/3sIYbfoXO.NKjW 1041920 bytes
ooxml_oleobject_00_ole10native_00.bin
5ae8cc190f0fef9895bb6f2b49ad62b935b0464e5d46526b85993a3281b7860d		 ole-package OOXML xl/embeddings/3sIYbfoXO.NKjW Ole10Native stream: Ole10nAtivE 1031275 bytes

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