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

Static analysis result for SHA-256 eca4e5db6bb4788a…

MALICIOUS

Office (OLE) / .XLSX

1.20 MB
MD5: 1e02b92b4285adf1f1973b20eb5b0a91 SHA-1: 31184f25596d0e32cdf343a9d993c547f95b7b4e SHA-256: eca4e5db6bb4788a6a07bc6774c82c3e64a95054f2d70e1810fad80bff3b2f3c
140 Risk Score

Malware Insights

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

The sample is an encrypted Excel spreadsheet that utilizes a default password, a common tactic for obfuscation. It contains an embedded Equation Editor OLE object, which is frequently used to deliver malicious payloads. The presence of an anomalous Ole10Native stream within the Equation Editor object strongly suggests it's being used as an exploit carrier. The specific exploit or payload is not directly discernible from the provided static analysis, hence the 'unknown family' classification.

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.