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

Static analysis result for SHA-256 4b2e04f07ddbbc25…

MALICIOUS

Office (OLE) / .XLSX

1.25 MB
MD5: b677902aa5e2126451dc6258e35d99f5 SHA-1: 2325d8d4c12de4fcd6b29c152cf4017983730198 SHA-256: 4b2e04f07ddbbc25db9260eac2de0d8ce45488b3a2c80de9c384b1abb014bbbd
140 Risk Score

Malware Insights

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

The sample is an encrypted OOXML file that contains embedded OLE objects, specifically identified as an Equation Editor exploit carrier. The presence of an 'OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY' heuristic indicates that the Equation Editor object is carrying a payload. This suggests the file is designed to exploit a vulnerability within the Equation Editor to execute malicious code, likely as a downloader or initial access vector.

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.