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

Static analysis result for SHA-256 a60f5da18b43cee8…

MALICIOUS

Office (OLE) / .XLSX

1.25 MB
MD5: a746a19a87ba1b76b2e453c0ac7131e9 SHA-1: 893dba0bd9b59d313207c3e91711988271306a8d SHA-256: a60f5da18b43cee8b11581668df2284a37361f16f1994f21e2c9dab8e48f8298
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample is an encrypted Office XLSX file that contains embedded OLE objects, specifically identified as Equation Editor objects. These objects are frequently used as exploit carriers. The presence of an 'OLE_EQUATION_EDITOR' and 'OOXML_ENCRYPTED_EXPLOIT_CARRIER_SHAPE' heuristic firing strongly suggests this file is designed to deliver a payload via an embedded exploit. No specific family could be identified, and no external IOCs were extracted.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Default-encrypted OOXML embedded OLE object xl/embeddings/oleObject1.bin contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
  • Default-encrypted OOXML exploit carrier layout high OOXML_ENCRYPTED_EXPLOIT_CARRIER_SHAPE
    Default-password encrypted OOXML package contains embedded OLE object parts and additional activation/decoy parts. This layout is common in malicious Excel exploit delivery and requires inspecting the decrypted package.
  • Equation Editor object carries payload-like Ole10Native stream high OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY
    Default-encrypted OOXML embedded OLE object declares the Equation Editor CLSID but stores a large high-entropy Ole10Native stream with malformed package sizing. This is exploit-shaped Equation/OLE payload evidence.
  • Office OOXML encrypted with default VelvetSweatshop password medium OFFICE_DEFAULT_PASSWORD_ENCRYPTED_OOXML
    OLE EncryptedPackage decrypts with Excel's built-in VelvetSweatshop password. Office opens this transparently, and malware uses it to hide OOXML exploit parts from scanners that only inspect the outer OLE container.