Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 269ea6a6039a4ed4…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:43:31 Authoring application: Microsoft Excel First seen: 2021-09-22
MD5: 8ae093b18c8a3b0176a431c5a09362cf SHA-1: a3e7ea1efcdd3adfe3a7ce4ddd3f50b577e21155 SHA-256: 269ea6a6039a4ed441a53bd73a9ab04b4d8085eebfbc7115c808baca69791198
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open defined name and dangerous formula APIs, specifically 'RUN'. This strongly suggests the macro is designed to execute commands. The presence of a macro sheet named 'lKwfESOZ' and the Auto_Open entry points to an attempt to automatically run malicious code upon opening the document. The macro likely downloads and executes a second-stage payload, a common technique for initial execution.

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.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6687 bytes
SHA-256: 11a88e1e0a28e178bdff86ad42bef21c2f3b6b335645929539812c58d030e7ed
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     16 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  lKwfESO
' 0018     27 LABEL : Cell Value, String Constant - ajjTpzvcrGpA len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C167 
' 0018     27 LABEL : Cell Value, String Constant - CRolyFuOwlsj len=0 
' 0018     23 LABEL : Cell Value, String Constant - CsoQqaLH len=0 
' 0018     21 LABEL : Cell Value, String Constant - cuILkb len=0 
' 0018     22 LABEL : Cell Value, String Constant - DhYRhth len=0 
' 0018     22 LABEL : Cell Value, String Constant - eJDdFdL len=0 
' 0018     27 LABEL : Cell Value, String Constant - ffirspKKMPEL len=0 
' 0018     21 LABEL : Cell Value, String Constant - gOEqcu len=0 
' 0018     20 LABEL : Cell Value, String Constant - hIIPo len=0 
' 0018     25 LABEL : Cell Value, String Constant - LIYYYzPyNh len=0 
' 0018     21 LABEL : Cell Value, String Constant - lmMjnt len=0 
' 0018     27 LABEL : Cell Value, String Constant - pLgBvYSCutaJ len=0 
' 0018     23 LABEL : Cell Value, String Constant - rseocvfI len=0 
' 0018     26 LABEL : Cell Value, String Constant - SYtdBOznaSx len=0 
' 0018     23 LABEL : Cell Value, String Constant - ubrEODHL len=0 
' 0018     21 LABEL : Cell Value, String Constant - uSzSxi len=0 
' 0018     24 LABEL : Cell Value, String Constant - uVqpOFerG len=0 
' 0018     21 LABEL : Cell Value, String Constant - vpWfwM len=0 
' 0018     21 LABEL : Cell Value, String Constant - VRiusp len=0 
' 0018     21 LABEL : Cell Value, String Constant - wgrZzs len=0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LA
... (truncated)

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