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

Static analysis result for SHA-256 8cae3f215be00916…

MALICIOUS

Office (OLE) / .XLSX

297.0 KB
MD5: 00a5a4f9263f3a677d66c5d8d9b87a0c SHA-1: b00c9993cbb7762b125b0340d1b9047b2e080fbb SHA-256: 8cae3f215be00916f4603adb69b3178ed32e35e5768d1b004bc0cc7eafcab704
180 Risk Score

Malware Insights

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

The sample is an encrypted Office document that utilizes an embedded Equation Editor OLE object. This object exhibits anomalies consistent with exploit delivery, specifically related to CVE-2018-0798. The presence of an exploit carrier within an encrypted document strongly suggests an attempt to deliver a malicious payload to the user upon opening.

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.