Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4e0e00850881f766…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:40:16 Authoring application: Microsoft Excel First seen: 2021-05-26
MD5: 2deb4afe3477a80bd81c70ce17d5fc81 SHA-1: a1a1019e55bc381f4963386698602cb5f82cbae6 SHA-256: 4e0e00850881f7669d29eab8746077ebaeb85586c4dd8d2ef88be1b2080015eb
140 Risk Score

Malware Insights

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

This Excel file contains Excel 4.0 (XLM) macros, specifically an Auto_Open defined name, which is a known technique for executing malicious code upon opening the workbook. The presence of dangerous formula APIs like RUN indicates an intent to execute arbitrary commands. The macro sheet itself is obfuscated, but the heuristic firings confirm the presence of an auto-execution entry.

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) 6594 bytes
SHA-256: adb4056cfa2b6f24284acb3e0d84d1325415d9557bb8e715faf4b4c73fe34187
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     16 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  NhVgRBM
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H132 
' 0018     24 LABEL : Cell Value, String Constant - BLeyCvlXC len=0 
' 0018     25 LABEL : Cell Value, String Constant - bUnQsHViTN len=0 
' 0018     24 LABEL : Cell Value, String Constant - feZXTRYZQ len=0 
' 0018     25 LABEL : Cell Value, String Constant - GtUKGoVArj len=0 
' 0018     24 LABEL : Cell Value, String Constant - IJSfFDgps len=0 
' 0018     25 LABEL : Cell Value, String Constant - JElGgelDXA len=0 
' 0018     26 LABEL : Cell Value, String Constant - KTPeAzSEAXe len=0 
' 0018     25 LABEL : Cell Value, String Constant - lQqIjbYtzp len=0 
' 0018     26 LABEL : Cell Value, String Constant - oxFcWxNRlpG len=0 
' 0018     22 LABEL : Cell Value, String Constant - PEiZXbZ len=0 
' 0018     25 LABEL : Cell Value, String Constant - ryDpyoxvFu len=0 
' 0018     23 LABEL : Cell Value, String Constant - tfZAqjUM len=0 
' 0018     24 LABEL : Cell Value, String Constant - TpBumbTeS len=0 
' 0018     20 LABEL : Cell Value, String Constant - UhmPv len=0 
' 0018     23 LABEL : Cell Value, String Constant - vvDdAYBY len=0 
' 0018     27 LABEL : Cell Value, String Constant - WgEbieNylpOo len=0 
' 0018     26 LABEL : Cell Value, String Constant - XgexzXFlLSx len=0 
' 0018     26 LABEL : Cell Value, String Constant - YRJdtHLJhNK len=0 
' 0018     25 LABEL : Cell Value, String Constant - ZHDTxEubyk len=0 
' 0018     20 LABEL : Cell Value, String Constant - zLxPw 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
... (truncated)

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