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

Static analysis result for SHA-256 2aaa20936c86d786…

MALICIOUS

Office (OLE) / .XLSX

966.0 KB
MD5: bfcc00f0c5560791011ff977b337a231 SHA-1: 53c0e5482d088b2f8f8cf159bcc1b718d4d1b9bd SHA-256: 2aaa20936c86d7863b2cc4097ac2195083d917cf01c8885c579e2d595e408eb2
140 Risk Score

Malware Insights

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

The sample is an encrypted OOXML file that contains an embedded Equation Editor OLE object. This object exhibits anomalies in its Ole10Native stream, suggesting it's being used as a carrier for a malicious payload. The default password encryption and the presence of the Equation Editor OLE object are common indicators of exploit 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.