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

Static analysis result for SHA-256 70a0259f53013655…

MALICIOUS

Office (OOXML) / .XLSX

730.5 KB Created: 2022-05-16 17:34:45 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2023-06-19
MD5: 6d9e1fcd9ae45d233550f73342574664 SHA-1: ec2cac21ab2d97c5f1cd0c3173f0eb26dc4accca SHA-256: 70a0259f530136555c14fbd2b93b36e5fbdf2cc55c8bbd7ecc2de5dffb5c1f10
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious File T1204.002 Malicious File: Malicious Attachment

The file is an Office Open XML spreadsheet containing an embedded OLE object, specifically identified as a Microsoft Equation Editor object. Heuristics indicate this object carries a payload-like stream with an anomalous header and a significantly larger declared size than the actual stream, strongly suggesting exploitation of a vulnerability within the Equation Editor. ClamAV detection confirms this as a downloader trojan.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/fhszUV3z.Vy 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
1391055222f3f709f74d3092f01a985dabafe0e40ba75421269d6c2216088f68		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/fhszUV3z.Vy 836608 bytes
ooxml_oleobject_00_ole10native_00.bin
3fbd3e3f09e7a0f0b596b22704f25d1443f7764f5c5156b5843d7f9c78d7e8e5		 ole-package OOXML xl/embeddings/fhszUV3z.Vy Ole10Native stream: oLE10NAtIVe 827873 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.