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

Static analysis result for SHA-256 6e327d2d70fdb77a…

MALICIOUS

Office (OLE) / .XLS

31.0 KB Created: 2020-12-08 13:42:08 Authoring application: Microsoft Excel
MD5: 11fc855dc2240599d354f095f4b43017 SHA-1: 277db6266cc8d5838b1bf1dd8330e1edcb5d6c56 SHA-256: 6e327d2d70fdb77a9cc5fc7e886c3c17e859ed305a143378b0c955b2425d9342
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample is an Excel 4.0 macro-enabled spreadsheet that uses an Auto_Open macro to execute. It contains a 'Macro/content-enable lure' heuristic, indicating it prompts the user to enable macros. The presence of dangerous formula APIs like RUN in the XLM macro suggests it is designed to execute arbitrary code, likely downloading a second-stage payload.

Heuristics 4

  • 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.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
9e38fa2da4304ee44378ab606fd3486f0510f94bc7da41e8f08993fbceb6cc0e
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3468 bytes