Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 5669732f7e2d6ccb…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:39:33 Authoring application: Microsoft Excel First seen: 2021-09-27
MD5: ea7fee561255184ee9284b9d7953f799 SHA-1: 83980753c2241186969eb69094f2e4906ffb1c57 SHA-256: 5669732f7e2d6ccbb4a005a8f2fd8dcc6ac904141866acc02c805c12a53b29e9
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 function, which is a known method for executing malicious code upon opening the workbook. The critical heuristics indicate the presence of dangerous formula APIs within the Auto_Open macro, suggesting it is designed to perform actions beyond simple spreadsheet operations. The macro likely attempts to download and execute a second-stage payload.

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) 6760 bytes
SHA-256: f83fdfdd179550c2a81937d3f978634c68a6ab4cbf41f9ef032ad9ba9a470336
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  KcNuT
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B150 
' 0018     22 LABEL : Cell Value, String Constant - bSgYJdF len=0 
' 0018     20 LABEL : Cell Value, String Constant - cSGic len=0 
' 0018     25 LABEL : Cell Value, String Constant - eLpYTWQurC len=0 
' 0018     22 LABEL : Cell Value, String Constant - FRYKvvP len=0 
' 0018     25 LABEL : Cell Value, String Constant - FUArcDMFNe len=0 
' 0018     24 LABEL : Cell Value, String Constant - HiqEchgLR len=0 
' 0018     27 LABEL : Cell Value, String Constant - hVwfrAJvwtBs len=0 
' 0018     23 LABEL : Cell Value, String Constant - HXnKfBYo len=0 
' 0018     24 LABEL : Cell Value, String Constant - iqTugWEGj len=0 
' 0018     23 LABEL : Cell Value, String Constant - iYbtFPfu len=0 
' 0018     27 LABEL : Cell Value, String Constant - jebudoYxfxeN len=0 
' 0018     20 LABEL : Cell Value, String Constant - kPBbk len=0 
' 0018     26 LABEL : Cell Value, String Constant - mGLgTlEfbVw len=0 
' 0018     26 LABEL : Cell Value, String Constant - OAKZypGHrOB len=0 
' 0018     26 LABEL : Cell Value, String Constant - PSkmdvVkvmq len=0 
' 0018     20 LABEL : Cell Value, String Constant - tUTUr len=0 
' 0018     22 LABEL : Cell Value, String Constant - VgXLVkP len=0 
' 0018     23 LABEL : Cell Value, String Constant - vpFjNtvq len=0 
' 0018     22 LABEL : Cell Value, String Constant - XYVUjQy len=0 
' 0018     22 LABEL : Cell Value, String Constant - zpfhWLC 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     1
... (truncated)

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