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

Static analysis result for SHA-256 35c2a725e954eb90…

MALICIOUS

Office (OLE) / .XLSX

1.22 MB
MD5: 9a8e2b20277c4eb838e777c5feeba629 SHA-1: 287be346176093ff13984499ac2a5fa53ad0104c SHA-256: 35c2a725e954eb909fab1a99eb53c044873465447804a32586cfd35efda9e3d2
140 Risk Score

Malware Insights

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

The OOXML document is encrypted with a default password and contains an Equation Editor OLE object. This object appears to be an exploit carrier, with an anomalous Ole10Native stream suggesting it contains a payload. The presence of these indicators strongly points to a malicious document designed to exploit vulnerabilities via the Equation Editor component.

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.