Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f46918953f945aee…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:42:16 Authoring application: Microsoft Excel First seen: 2021-09-27
MD5: c2eb1a715ba67898ee5f8c3b611298bd SHA-1: f4e0f58002c684e825561c2fa7cd36a58c15a38f SHA-256: f46918953f945aee0519dd02fcb503e2eba2e36d9a0f18738bc5dac68c68b26c
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. Heuristics indicate the presence of an Auto_Open macro that utilizes dangerous formula APIs, specifically identified as 'RUN'. This strongly suggests the macro is designed to execute arbitrary code, likely downloading and running a second-stage payload. The obfuscated document body content does not provide further clues on the specific lure.

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) 6710 bytes
SHA-256: 81ffbfc0859557e82120fec2507bc531f3be2c8674424917586144426d8defb5
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 -  CvVuAxNQTkZ
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!E160 
' 0018     23 LABEL : Cell Value, String Constant - BpKdPejI len=0 
' 0018     27 LABEL : Cell Value, String Constant - bPPaOVjpuCOH len=0 
' 0018     23 LABEL : Cell Value, String Constant - cXEahKYO len=0 
' 0018     25 LABEL : Cell Value, String Constant - DRitKnHBlP len=0 
' 0018     20 LABEL : Cell Value, String Constant - dtQEg len=0 
' 0018     27 LABEL : Cell Value, String Constant - EGVbadbyVnJG len=0 
' 0018     20 LABEL : Cell Value, String Constant - EwvlY len=0 
' 0018     21 LABEL : Cell Value, String Constant - jFwXdW len=0 
' 0018     27 LABEL : Cell Value, String Constant - JWdFTnBBPSXx len=0 
' 0018     26 LABEL : Cell Value, String Constant - khGHrQekBTw len=0 
' 0018     20 LABEL : Cell Value, String Constant - kxekk len=0 
' 0018     24 LABEL : Cell Value, String Constant - liygPTwlf len=0 
' 0018     27 LABEL : Cell Value, String Constant - PJkCYRsAQefr len=0 
' 0018     21 LABEL : Cell Value, String Constant - RaoKVK len=0 
' 0018     23 LABEL : Cell Value, String Constant - RIuUDDSu len=0 
' 0018     23 LABEL : Cell Value, String Constant - sgVFGwZE len=0 
' 0018     24 LABEL : Cell Value, String Constant - uFVouiMdM len=0 
' 0018     24 LABEL : Cell Value, String Constant - uJrfaRILK len=0 
' 0018     20 LABEL : Cell Value, String Constant - voyRD len=0 
' 0018     22 LABEL : Cell Value, String Constant - xnqghaA 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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