Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 e640a9b43396bcea…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:45:52 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: d36e35036010bdff6216eb0f03a91557 SHA-1: af2ecedb8e0b3de360cbc8e68956bd55dbb725fc SHA-256: e640a9b43396bcead10e35e6781819367192d198283a33cc6e2a4ca5ffb3d017
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) 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 arbitrary code, likely a second-stage payload. No specific family could be identified, but the execution method is clear.

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) 6629 bytes
SHA-256: 2f28cb88a06ad32cf808efec10c9d5d69307b0fe7d6257cbeaceb1bab5fe8063
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 -  rsUsofPZDDQ
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I184 
' 0018     21 LABEL : Cell Value, String Constant - BxyAab len=0 
' 0018     23 LABEL : Cell Value, String Constant - gLIQWrbX len=0 
' 0018     27 LABEL : Cell Value, String Constant - gUphKzlJDQwg len=0 
' 0018     23 LABEL : Cell Value, String Constant - ILxQzrdg len=0 
' 0018     20 LABEL : Cell Value, String Constant - jAJcI len=0 
' 0018     23 LABEL : Cell Value, String Constant - KFoBMLUE len=0 
' 0018     21 LABEL : Cell Value, String Constant - pTKcMC len=0 
' 0018     26 LABEL : Cell Value, String Constant - pUDKIdoctgZ len=0 
' 0018     27 LABEL : Cell Value, String Constant - PvmebgxDiOJJ len=0 
' 0018     27 LABEL : Cell Value, String Constant - sCLliWVfOOJw len=0 
' 0018     23 LABEL : Cell Value, String Constant - SqwVKMRe len=0 
' 0018     20 LABEL : Cell Value, String Constant - STEAC len=0 
' 0018     22 LABEL : Cell Value, String Constant - TYXOjYn len=0 
' 0018     21 LABEL : Cell Value, String Constant - UIFysT len=0 
' 0018     25 LABEL : Cell Value, String Constant - UnOnIvetEn len=0 
' 0018     24 LABEL : Cell Value, String Constant - VWLekpZog len=0 
' 0018     21 LABEL : Cell Value, String Constant - wNtNQG len=0 
' 0018     21 LABEL : Cell Value, String Constant - XgvCzN len=0 
' 0018     23 LABEL : Cell Value, String Constant - xjdcHYfD len=0 
' 0018     24 LABEL : Cell Value, String Constant - yjHylkfsR 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
... (truncated)

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