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

Static analysis result for SHA-256 2b756d0e28c6dc4e…

MALICIOUS

Office (OLE) / .XLSX

1.31 MB
MD5: 737fcc361993ff90106cd58964a02a40 SHA-1: d2acd84a5926dc0ab714b87b319e923e0e90c34b SHA-256: 2b756d0e28c6dc4ed3989fdf7044ebc02652f331242e4d5981a165b05b6e39b8
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 embedded Equation Editor OLE object. This object exhibits anomalies indicative of a malicious payload, specifically an 'Ole10Native' stream with an impossible header and a declared inner size far exceeding the actual stream size. This strongly suggests the Equation Editor is being used as an exploit carrier, likely to execute arbitrary code.

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.