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

Static analysis result for SHA-256 4b4a2ef593425b8b…

MALICIOUS

Office (OLE) / .XLSX

468.0 KB
MD5: e00c1ea0cd7016eabb3f50361d9aa132 SHA-1: 613f1ac5182703ac543b9a95b56737d72820cc7a SHA-256: 4b4a2ef593425b8beebedfbd78c6ba48996d7d141d0579da24558d7b1d5dfb55
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious File T1559 Component Object Model Hijacking T1559.001 Component Object Model Hijacking: Component Object Model Hijacking

The sample is an OOXML file that is encrypted with a default password, indicating an attempt to evade static analysis. It contains an Equation Editor OLE object that exhibits anomalies consistent with CVE-2018-0798, a known vulnerability. This suggests the file is designed to exploit this vulnerability to execute arbitrary code, likely as a downloader for further malicious activity.

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.
  • 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.
  • 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.