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

Static analysis result for SHA-256 e6de55ef568521e2…

MALICIOUS

Office (OLE) / .XLSX

1.22 MB
MD5: f683a8eb2e17866a194af9b23efda095 SHA-1: b3002f93d24336a9af003a7a3da36217a7d7b8db SHA-256: e6de55ef568521e22566496d9df49eb1a4cf2ea94082d8d0bcd357f41d2962ef
140 Risk Score

Malware Insights

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

The sample is an encrypted Excel file that utilizes embedded OLE objects, with a high-confidence detection of an Equation Editor OLE object. This object appears to carry a payload within its Ole10Native stream, indicating it's likely an exploit carrier. The encryption with a default password further suggests an attempt to evade 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.