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

Static analysis result for SHA-256 27c77a8ecf03c362…

MALICIOUS

Office (OOXML) / .XLSX

725.9 KB Created: 2020-08-20 17:59:18 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-09-05
MD5: d594fd1995f1c49ba407a7c913807522 SHA-1: 64a2112c3649db1b72cf6f4738ebe9803e06ef19 SHA-256: 27c77a8ecf03c36235b8f27af6d52e2204ba315bbedf09a72010e3821ffae897
108 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 User Execution: Malicious File

The file is an Excel document containing an embedded Equation Editor OLE object. This object has an anomalous Ole10Native stream, indicating it likely carries a malicious payload. The document body contains text resembling invoices and payment details, suggesting a lure to trick the user into interacting with the malicious object. The presence of the Equation Editor OLE object is a strong indicator of exploitation, likely for initial payload delivery.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/40YHdytk2.Uoaylx 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
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
ooxml_oleobject_00.bin
10be97d30a4eeac45fed5483e80b617ce047d3e1d513bf9c1958a0f5816d0f1f		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/40YHdytk2.Uoaylx 905728 bytes
ooxml_oleobject_00_ole10native_00.bin
4ff051ba5f78c2e61d97a92f6c4907aa78f0a3f5ee180d4eed1c7e3ac40b435d		 ole-package OOXML xl/embeddings/40YHdytk2.Uoaylx Ole10Native stream: OlE10nAtive 896230 bytes

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