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

Static analysis result for SHA-256 98d70d380e47e322…

MALICIOUS

Office (OLE) / .XLS

62.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: bdddcb83eb34b845c63236217d8c66c1 SHA-1: 9b72a4af30cd5c2ae16bcdcf7b08ca261060e9a6 SHA-256: 98d70d380e47e322a27acacfde174992bb5209fcad2bca06fc02052fce325b66
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1218.010 System Binary Proxy Execution: Regsvr32 T1566.001 Phishing: Spearphishing Attachment T1140 Deobfuscate/Decode Files or Information

The sample is an Excel 4.0 macro-enabled workbook designed to impersonate a DocuSign request, luring the user to enable macros. Upon enabling, it uses a defined name 'Auto_Open' to execute a command that leverages regsvr32.exe to load and execute a DLL from the path C:\LotWin\LotWin2\Horsew.dll. The presence of the URL http://zona-relax.ru/irojrjejofvr/ suggests it may be involved in downloading or hosting the malicious payload.

Heuristics 5

  • 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.
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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
  • Document signing service impersonation lure medium SE_DOCUSIGN_LURE
    Document impersonates DocuSign, Adobe Sign, or a similar signing service in a signing-request context

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
ca514918e1c8c675022f49ba3856791a601f976c7085cf5920e0fc2bfdb2d209
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 2212 bytes