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

Static analysis result for SHA-256 5a1784b55c80ced6…

MALICIOUS

Office (OLE) / .XLSX

1.22 MB
MD5: 86cc81a767daa9f5e93faddc3204f5ce SHA-1: 75affb1f06e89d386d527da92f52225e273afbc5 SHA-256: 5a1784b55c80ced6950dd066f3ddf5fb59d9a42e7493895527166bd2676c3445
140 Risk Score

Malware Insights

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

The sample is an encrypted OOXML file that utilizes a default password, a common technique for obfuscating malicious content. It contains an embedded Equation Editor OLE object, identified as a high-confidence exploit carrier. This object exhibits anomalies in its Ole10Native stream size and entropy, strongly suggesting it contains a malicious payload. The presence of these indicators points towards a spearphishing attachment designed to deliver an exploit.

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.