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

Static analysis result for SHA-256 d1ab1685c705b672…

MALICIOUS

Office (OLE) / .XLSX

1.47 MB
MD5: 3f2880dd1adcaa13e5e161411f7543ed SHA-1: 135c075625c4385f5e8271fd2cee6c447a4b9e1d SHA-256: d1ab1685c705b672b7ff8085e2294decd58345d14d69bb883e0a940bf31e040a
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 Equation Editor OLE object, a known carrier for exploits. The OLE object exhibits anomalies suggesting it carries a malicious payload within its Ole10Native stream. The default password encryption further indicates an attempt to obscure the malicious content. The exploit likely targets a vulnerability within the Equation Editor, leading to the execution of a second-stage 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.