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

Static analysis result for SHA-256 1f9381182aad4f99…

MALICIOUS

Office (OLE) / .XLSX

1.30 MB
MD5: 615f2501445e5068912051a1bc11d382 SHA-1: b05c6a1ce1aa0b551e8837a8b00f55aff46ae2a5 SHA-256: 1f9381182aad4f9917a66438b10d69f62c1027e3e4d27477c48cdec6651bd0d8
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious File T1559.001 Component Object Model

The sample is an OOXML file that is encrypted with a default password and contains embedded OLE objects, specifically identified as Equation Editor objects. These objects carry a payload-like Ole10Native stream, indicating they are likely used to exploit a known vulnerability in the Equation Editor component to execute arbitrary code. No document body text was available for analysis, but the heuristic firings strongly suggest a classic exploit carrier.

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.