Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3a706386eae82d84…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:40:09 Authoring application: Microsoft Excel First seen: 2021-10-05
MD5: ee5127ef26fe3f541b3c3659aa538ecb SHA-1: 1e975c29e5fe1af7d62e0e5a045f24ccb331ab4a SHA-256: 3a706386eae82d846480c5c3f350a4e4c4b44f0de4d4330b01d78bb0a0b5387a
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 macros, specifically an Auto_Open function. This function is designed to execute arbitrary code upon opening the workbook, which is a common technique for delivering secondary payloads. The presence of dangerous formula APIs like RUN further indicates malicious intent.

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) 6643 bytes
SHA-256: 5042208e2a79ff14f3e2c2cea77f3d9d49ee53e6356373929f658688c5e2de4d
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  AtbJiVzOYyY
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A152 
' 0018     21 LABEL : Cell Value, String Constant - BMqIZg len=0 
' 0018     22 LABEL : Cell Value, String Constant - CCyTdPD len=0 
' 0018     20 LABEL : Cell Value, String Constant - eHKvY len=0 
' 0018     21 LABEL : Cell Value, String Constant - eteOdu len=0 
' 0018     21 LABEL : Cell Value, String Constant - eUmbrs len=0 
' 0018     26 LABEL : Cell Value, String Constant - GnZaxAiQAXA len=0 
' 0018     20 LABEL : Cell Value, String Constant - KSiBB len=0 
' 0018     26 LABEL : Cell Value, String Constant - lpLTdMIKQcQ len=0 
' 0018     21 LABEL : Cell Value, String Constant - myKgZk len=0 
' 0018     21 LABEL : Cell Value, String Constant - oPqbPK len=0 
' 0018     22 LABEL : Cell Value, String Constant - SvjqaRX len=0 
' 0018     22 LABEL : Cell Value, String Constant - sxYESOM len=0 
' 0018     25 LABEL : Cell Value, String Constant - vvljfHFmYt len=0 
' 0018     23 LABEL : Cell Value, String Constant - wfUPSTDf len=0 
' 0018     22 LABEL : Cell Value, String Constant - WguFLYq len=0 
' 0018     26 LABEL : Cell Value, String Constant - xCfxyhkjXTV len=0 
' 0018     26 LABEL : Cell Value, String Constant - XHFypEOpUNd len=0 
' 0018     23 LABEL : Cell Value, String Constant - yMimuewy len=0 
' 0018     23 LABEL : Cell Value, String Constant - YqKsnWfy len=0 
' 0018     22 LABEL : Cell Value, String Constant - YvpVycT 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 LABELSST
... (truncated)

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