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

Static analysis result for SHA-256 3a8ac2f64fd8b15e…

MALICIOUS

Office (OLE) / .XLS

61.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 026e352321bacf5fb2cc6eb4002b26ae SHA-1: a27c9d892aeccb3759fbf71d21404befabbdd431 SHA-256: 3a8ac2f64fd8b15e4f88db0c54add4fd61e5c17dd5515ada898006169e2f99f2
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1566.001 Spearphishing Attachment T1059.001 PowerShell T1218.011 Rundll32

The sample is an Excel 4.0 macro-enabled spreadsheet that uses an Auto_Open macro to execute. It impersonates DocuSign to trick the user into enabling macros. The macro then uses 'rundll32 C:\AutoCadest\AutoCadest2\Fiksat.dll, DllRegisterSe' to execute a payload, likely 'C:\AutoCadest\AutoCadest2\Fiksat.exe', from a suspicious URL. The presence of the Auto_Open macro and the execution chain strongly indicate a malicious downloader.

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
075072a41717adc301f689cf06a6c75f7ae4978d8de5ff68a306276ec79c0f60		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 2718 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.