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

Static analysis result for SHA-256 96dfbd66f0f66fcd…

MALICIOUS

Office (OLE) / .XLSX

1.31 MB
MD5: 487ad1263c69b646deea3281714af9d7 SHA-1: 646cb98c26ba3dda514a8e096563e90e0ee420f1 SHA-256: 96dfbd66f0f66fcde3a600b7fba76137e246e946e5dc90f4bfc849125e16cb62
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566 Phishing T1204.001 Malicious Link: Malicious File T1566.001 Phishing: Spearphishing Attachment T1059 Command and Scripting Interpreter

The sample is an OOXML file that is encrypted with a default password and contains an Equation Editor OLE object. This object carries a payload-like stream, indicating it's likely used to exploit a vulnerability, such as CVE-2017-11882, to execute arbitrary code. No specific scripts or URLs were extracted, but the presence of the Equation Editor exploit carrier strongly suggests a malicious intent to deliver a secondary payload.

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.