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

Static analysis result for SHA-256 3f840c0e17bf2968…

MALICIOUS

Office (OLE) / .XLSX

274.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2022-09-22
MD5: 73939b592837a03a66266b231fab3546 SHA-1: 9b0741b80dd8a17d9a1fbefc5518760fd20bce71 SHA-256: 3f840c0e17bf29685179a11682e919c4bb7313ca8309c68a675b56684bb9a508
122 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.005 Visual Basic T1204.002 Malicious File

The sample contains Excel 4.0 macros, including an Auto_Open entry, which is a strong indicator of malicious intent. It also employs a lure to trick users into enabling macros by impersonating a document signing service. The embedded URL, https://emploimed.com/netr.dll, is likely used to download and execute a secondary payload.

Heuristics 5

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • Document signing service impersonation lure medium SE_DOCUSIGN_LURE
    Document impersonates DocuSign, Adobe Sign, or a similar signing service in a signing-request context
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://emploimed.com/netr.dll

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
0e5eb114c8fd5abcfe2f4fcc65b4470ea3e595e7167c7bbcfac8278ee143a695
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3709 bytes