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

Static analysis result for SHA-256 53e9e6bf16ec7de0…

MALICIOUS

Office (OOXML) / .XLSX

786.9 KB Created: 2022-05-16 17:34:45 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2023-01-25
MD5: f7373b286f49dd2fc1ac3c159a4499e4 SHA-1: a2d48efd2fb41c69049e1ef800ec91fcc87ff1f8 SHA-256: 53e9e6bf16ec7de032956a0a87d9fadec380be59a5c75672aa36cfdd2da7a803
160 Risk Score

Malware Insights

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

The critical ClamAV detection and high-severity heuristics indicate this XLSX file is malicious. It contains an embedded Equation Editor OLE object that carries a payload-like stream, suggesting it's designed to deliver a secondary malicious component. The anomaly in the Ole10Native stream size further supports this malicious intent.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/bm.avITjZ 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
d20ca099753401fba383a657a35e136d4146933d941e85601d5c89a47bb2d4ec		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/bm.avITjZ 946176 bytes
ooxml_oleobject_00_ole10native_00.bin
af48fd9dd18aa2ab979b1aba4da28d060cb7a7660e4f4a7cf4996f064bb33a71		 ole-package OOXML xl/embeddings/bm.avITjZ Ole10Native stream: OLe10nATiVe 936220 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.