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

Static analysis result for SHA-256 b05951994381eb4d…

MALICIOUS

Office (OOXML) / .XLSX

805.6 KB Created: 2022-05-16 17:34:45 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2023-03-17
MD5: e00884af2e09405dada9c65994d9a6cb SHA-1: 3a0071ce7a0056f82304ab9b81c1dccf802496c7 SHA-256: b05951994381eb4d953d58b7ffa7c428be1f640d8c70d70adbfb4a046fb6dc6c
160 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and exhibits high-severity heuristics related to an embedded Equation Editor OLE object. This object contains an anomalous Ole10Native stream, suggesting it carries a payload. The embedded OLE object is the primary indicator of malicious intent, likely serving as a dropper for a secondary stage.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/2tNgdazw.ztD contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
  • ClamAV: Xls.Downloader.Trojan-aa0b8f388d8573cd-aa0b8f388d8573cd-9950439-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Trojan-aa0b8f388d8573cd-aa0b8f388d8573cd-9950439-0
  • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
ooxml_oleobject_00.bin
ae91bd8e972e6f923e70bf934bd6bea037c22aeb4470558fabd61982bfb1f102		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/2tNgdazw.ztD 973312 bytes
ooxml_oleobject_00_ole10native_00.bin
b89c6e4fc003dcae0ea8dcbe8678e185490f81e4f1ec280f3fa50dce5ebe8a4e		 ole-package OOXML xl/embeddings/2tNgdazw.ztD Ole10Native stream: olE10naTiVE 963546 bytes
emf_00.emf
38f17a599ac5d645df3840bbb401710ef81573a747da20abbfc1b7d9a9273b58		 ooxml-emf OOXML EMF part: xl/media/image1.emf 169096 bytes

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