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

Static analysis result for SHA-256 8d9987b12667c1d3…

MALICIOUS

Office (OOXML) / .XLSX

644.7 KB Created: 2023-01-19 05:24:18 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2023-01-25
MD5: be7a9bc01cfea694a22d463ec14e7e3b SHA-1: 1bc1b452bb230be5d4a51484ff4f2771f3792619 SHA-256: 8d9987b12667c1d3cfd71161c7d18fe4b152557157bed38264120baa49b184be
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious File

The sample is an Excel file containing an embedded OLE object, specifically identified as a Microsoft Equation Editor object. High-severity heuristics indicate that this object is anomalous and carries a payload, strongly suggesting exploitation of CVE-2018-0798. This technique is commonly used to deliver second-stage malware.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/5lotd.pGWtW 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
    Embedded Equation Editor OLE data contains anomalous native stream bytes consistent with a CVE-2018-0798-style Equation Editor exploit. This is treated as likely CVE evidence because the Equation object is malformed and payload-like, but it does not match the exact public matrix-overflow byte signature.
  • Equation Editor object carries payload-like Ole10Native stream high OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY
    Embedded OLE object declares the Equation Editor CLSID but stores a large high-entropy Ole10Native stream with malformed package sizing. This is an exploit-shaped Equation/OLE payload container seen in malicious OOXML samples. It is not assigned to a specific CVE unless the MTEF/Equation Native primitive also matches.
  • Embedded OLE object medium OOXML_OLE_OBJECT
    Document contains an embedded OLE object

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
ooxml_oleobject_00.bin
f5f358bed141b27215240ed5958ee652c5a815d8d2463c393be51c62d12cbac6		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/5lotd.pGWtW 889856 bytes
ooxml_oleobject_00_ole10native_00.bin
b5763762c944aaa8d13395370975f297695a7a77f576a5d70f0b76541322d569		 ole-package OOXML xl/embeddings/5lotd.pGWtW Ole10Native stream: OLe10NATIVe 880205 bytes

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