Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3a7c9efa418e7902…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:39:29 Authoring application: Microsoft Excel First seen: 2021-10-05
MD5: 00961b6e32b712b30d0850b0fcfcc109 SHA-1: 6d09fc1068a5646f8ca6ae8d27fca14e2e41fdf5 SHA-256: 3a7c9efa418e79020a0bbc9c1a41878857804f4170457b1e9d763c03ea81e593
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook containing an Auto_Open function. This function is designed to automatically execute when the workbook is opened, indicating an attempt to run malicious code. The presence of dangerous formula APIs within the macro sheet further supports this, suggesting the macro is intended to download and execute a secondary 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) 6555 bytes
SHA-256: 7d6861b0c1271a1ad9d28dcf0174b2e7ebff45a6a6513df2aa86227a7d77a784
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     12 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  Cyt
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D154 
' 0018     23 LABEL : Cell Value, String Constant - cYoEbFMd len=0 
' 0018     26 LABEL : Cell Value, String Constant - dHpxalcDCix len=0 
' 0018     26 LABEL : Cell Value, String Constant - EVEbXtLDyMS len=0 
' 0018     20 LABEL : Cell Value, String Constant - eWXSd len=0 
' 0018     25 LABEL : Cell Value, String Constant - hiohqIILso len=0 
' 0018     27 LABEL : Cell Value, String Constant - jopYipGiLVJC len=0 
' 0018     20 LABEL : Cell Value, String Constant - jvIpa len=0 
' 0018     21 LABEL : Cell Value, String Constant - LTPQZS len=0 
' 0018     23 LABEL : Cell Value, String Constant - mTaCRohu len=0 
' 0018     20 LABEL : Cell Value, String Constant - Nbizl len=0 
' 0018     27 LABEL : Cell Value, String Constant - oRakOFzJUnla len=0 
' 0018     21 LABEL : Cell Value, String Constant - rGNYfQ len=0 
' 0018     26 LABEL : Cell Value, String Constant - RwmaJLLCEzW len=0 
' 0018     27 LABEL : Cell Value, String Constant - rypHmCCvYweh len=0 
' 0018     22 LABEL : Cell Value, String Constant - sPGtuuY len=0 
' 0018     25 LABEL : Cell Value, String Constant - uNMNGbAdEt len=0 
' 0018     23 LABEL : Cell Value, String Constant - vvvwxlNw len=0 
' 0018     26 LABEL : Cell Value, String Constant - WFkZkBgYlEr len=0 
' 0018     23 LABEL : Cell Value, String Constant - zwoCKiPI len=0 
' 0018     22 LABEL : Cell Value, String Constant - zyGnDYl 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)