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

Static analysis result for SHA-256 d5917dcf259b918a…

MALICIOUS

Office (OLE) / .XLSX

939.0 KB
MD5: c7460702ea382e96fb9fd1c78b3845ce SHA-1: 139ff70d1126d2c958023e86b29b43600302506f SHA-256: d5917dcf259b918abe37b72bc45551cdb5d4c33da80c2c517f15097c71554c74
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566.001 Spearphishing Attachment

The sample is an encrypted OOXML file that contains an embedded Equation Editor OLE object. This object is known to be used to exploit vulnerabilities, likely for initial payload delivery. No specific family could be identified, and no direct IOCs like URLs or hashes were extracted from the static analysis.

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.