Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 58f949b61261b878…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:41:42 Authoring application: Microsoft Excel First seen: 2021-09-29
MD5: c027e0608bca5e1afbc67bc1a25fde61 SHA-1: 10085469690b7cb242edc675450106f983311ba8 SHA-256: 58f949b61261b87800331e637b8a3ac8fc988193114792a4f5ef05700eba1be9
140 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro sheet that contains an Auto_Open defined name, indicating it is designed to execute automatically upon opening. Heuristics also identified dangerous formula APIs within the macro sheet, suggesting it attempts to perform actions beyond standard spreadsheet operations. The presence of an Auto_Open entry and the use of dangerous functions strongly suggest an attempt to execute arbitrary code.

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) 6722 bytes
SHA-256: d768e27550b929dfd7b1d7a26fef481340e74858abe9a40f4cdbd0516dd12d1f
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  AKIRgvGw
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H155 
' 0018     20 LABEL : Cell Value, String Constant - AwZgN len=0 
' 0018     26 LABEL : Cell Value, String Constant - cWDGHsSxklX len=0 
' 0018     25 LABEL : Cell Value, String Constant - cYzxeQlQct len=0 
' 0018     26 LABEL : Cell Value, String Constant - eGMzApOJrir len=0 
' 0018     27 LABEL : Cell Value, String Constant - gWzXrqPkYtLz len=0 
' 0018     22 LABEL : Cell Value, String Constant - hqXYslz len=0 
' 0018     22 LABEL : Cell Value, String Constant - JuarnIG len=0 
' 0018     22 LABEL : Cell Value, String Constant - LyEydWw len=0 
' 0018     21 LABEL : Cell Value, String Constant - mnJBQQ len=0 
' 0018     21 LABEL : Cell Value, String Constant - nimrqv len=0 
' 0018     23 LABEL : Cell Value, String Constant - PwuXXJmO len=0 
' 0018     23 LABEL : Cell Value, String Constant - TnYKkgtg len=0 
' 0018     23 LABEL : Cell Value, String Constant - UjTbMhhY len=0 
' 0018     27 LABEL : Cell Value, String Constant - utPPuibZlfma len=0 
' 0018     26 LABEL : Cell Value, String Constant - WcZvRdiRfDN len=0 
' 0018     23 LABEL : Cell Value, String Constant - wNadXcGe len=0 
' 0018     27 LABEL : Cell Value, String Constant - XxuphNPPIWXk len=0 
' 0018     20 LABEL : Cell Value, String Constant - znXDw len=0 
' 0018     24 LABEL : Cell Value, String Constant - ZsrJvQZxc len=0 
' 0018     20 LABEL : Cell Value, String Constant - ZYXxK 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    
... (truncated)