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

Static analysis result for SHA-256 ca667eed4db141ad…

MALICIOUS

Office (OLE) / .XLSX

2.47 MB
MD5: ecb4fb80b8777c937ecacbbe08c22c54 SHA-1: 63d8d86ba815b7cc39b86efa9804e1e9489b1f51 SHA-256: ca667eed4db141ad31216200f15c197e6ef4c3e3230ead7b84f0174abf5397dd
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566 Phishing 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, which is frequently exploited. Specifically, the 'CVE_2018_0798_EQUATION_NATIVE_ANOMALY' and 'OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY' heuristics indicate the presence of an anomalous Equation Editor native stream, strongly suggesting it's designed to deliver a payload. The lack of document body text and scripts means the exact payload delivery mechanism cannot be determined from this analysis alone.

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.