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

Static analysis result for SHA-256 37d4aff454b7ae13…

MALICIOUS

Office (OLE) / .XLSX

2.54 MB
MD5: af5b1d5cb1d2b6116828257e9177256a SHA-1: e156a7dbd7b6050ceca5d85c067ce8693ad21e8e SHA-256: 37d4aff454b7ae13112ee51ab56a05f47ae3e7bb07c04474df2ff41d4a875c13
180 Risk Score

Malware Insights

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

The file is an encrypted OOXML document containing an embedded Equation Editor OLE object. Heuristics indicate this object is anomalous and likely carries a malicious payload, exploiting CVE-2018-0798. The encryption and the nature of the exploit suggest a downloader or dropper functionality, aiming to execute further malicious code.

Heuristics 5

  • 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.
  • CVE-2018-0798 — anomalous Equation Editor native stream high CVE likely CVE_2018_0798_EQUATION_NATIVE_ANOMALY
    Default-encrypted OOXML contains embedded Equation Editor data with anomalous native stream bytes consistent with a CVE-2018-0798-style exploit. This is treated as likely CVE evidence because the Equation object is malformed and payload-like.
  • 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.

Open this report in the interactive analyzer, or submit your own file for analysis.