Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 9f263e0ba392c7c1…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:47:50 Authoring application: Microsoft Excel First seen: 2021-07-07
MD5: 55e5e65552169e5563fc5b537c8130fd SHA-1: 5f8f9984f86e1ad81f62c3943d386224331eb49e SHA-256: 9f263e0ba392c7c1e6bdb027fc3bec115dd158448d5c340e85e5b3ef5d1574d1
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding indicating automatic execution upon opening. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute external code. This is a common technique for delivering secondary payloads, making it highly likely that this macro serves as a downloader.

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) 6918 bytes
SHA-256: 8f735b8a5c42cb10c140300701a16b263e9a5252e5ab2ec9c85da175f9d3c350
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 -  bjrpjFoQUuU
' 0018     26 LABEL : Cell Value, String Constant - AggIltanssO len=0 
' 0018     27 LABEL : Cell Value, String Constant - ARTnSGYvCUpC len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C180 
' 0018     24 LABEL : Cell Value, String Constant - bQRfSJpmb len=0 
' 0018     20 LABEL : Cell Value, String Constant - cLQVe len=0 
' 0018     25 LABEL : Cell Value, String Constant - dpBLPfLtbw len=0 
' 0018     21 LABEL : Cell Value, String Constant - FruqZr len=0 
' 0018     20 LABEL : Cell Value, String Constant - jDyZm len=0 
' 0018     23 LABEL : Cell Value, String Constant - JHgxxADz len=0 
' 0018     22 LABEL : Cell Value, String Constant - MsrKrjD len=0 
' 0018     27 LABEL : Cell Value, String Constant - nfwkppzYZiAz len=0 
' 0018     23 LABEL : Cell Value, String Constant - OiBdjTez len=0 
' 0018     20 LABEL : Cell Value, String Constant - qBWuT len=0 
' 0018     25 LABEL : Cell Value, String Constant - qCcRkKRxOe len=0 
' 0018     27 LABEL : Cell Value, String Constant - rYAjdBJKRNTJ len=0 
' 0018     20 LABEL : Cell Value, String Constant - sXqKT len=0 
' 0018     23 LABEL : Cell Value, String Constant - uFIvGapc len=0 
' 0018     23 LABEL : Cell Value, String Constant - uwNRfVok len=0 
' 0018     26 LABEL : Cell Value, String Constant - WaqTrFMvlCG len=0 
' 0018     23 LABEL : Cell Value, String Constant - WURClKub len=0 
' 0018     21 LABEL : Cell Value, String Constant - znmZuf 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)

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