MALICIOUS
180
Risk Score
Malware Insights
MITRE ATT&CK
T1566.001 Spearphishing Attachment
T1059.005 Visual Basic
T1105 Ingress Tool Transfer
The sample is an Excel 97-2003 Workbook containing Excel 4.0 macros, which is a strong indicator of malicious intent. The document body and heuristics indicate a lure to impersonate DocuSign and trick the user into enabling macros. The presence of the URLDownloadToFileA API call and the extracted URL suggest the macro is designed to download and execute a second-stage payload, likely named 'nkfkdsn.exe'.
Heuristics 5
-
Reference to URLDownloadToFile API critical SC_STR_URLDOWNLOADReference to URLDownloadToFile API
-
Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAMEoletools 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_AUTOOPENWorkbook 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_LUREDocument 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_LUREDocument impersonates DocuSign, Adobe Sign, or a similar signing service in a signing-request context
Extracted artifacts 1
Files carved from inside the sample during analysis.
| Filename | Kind | Source | Size |
|---|---|---|---|
xlm_macros.txtd33eb6c8974f3fadc0d24b070cfaac148934097838128fa136473cb6f16899c1 |
xlm-macro | oletools.olevba.extract_all_macros (XLM macro listing) | 1187 bytes |
Open this report in the interactive analyzer, or submit your own file for analysis.