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

Static analysis result for SHA-256 53499e04068f8d12…

MALICIOUS

Office (OLE) / .XLSX

1.49 MB
MD5: db52dfb1c82a7b9fab22d0a297c0764f SHA-1: dfda9fb61b3c140010b1df004a91f3c16ae247a5 SHA-256: 53499e04068f8d1217e291c2d7fbce4d236db4f107b40f807fcefd86c1ded797
140 Risk Score

Malware Insights

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

The file is an encrypted Excel spreadsheet that uses a default password, a common tactic for hiding malicious content. It contains an embedded OLE object, specifically identified as an Equation Editor exploit carrier. This strongly suggests the file is designed to leverage a known vulnerability within the Equation Editor to execute a payload.

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.