Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 42dd4bb9b14e2ff5…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:45:32 Authoring application: Microsoft Excel First seen: 2021-11-03
MD5: c181ca25fae09d534a577d4830dc310c SHA-1: b45425a154294d10899d4274159367ae4ca202d0 SHA-256: 42dd4bb9b14e2ff5780b742c11568ff86b6bd1743b704d432a4a1e08e08374d4
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 defined name, which is a critical finding indicating automatic execution upon opening. The presence of dangerous formula APIs, including the RUN function, suggests the macro is designed to execute arbitrary commands. This is a common technique for downloading and executing further malicious content.

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) 6616 bytes
SHA-256: ae609af1656f19c0b25f2a13346b5fcee440636800034e566fbeb6e99bf13489
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     19 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  rortmhcPmc
' 0018     20 LABEL : Cell Value, String Constant - aohuw len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B171 
' 0018     26 LABEL : Cell Value, String Constant - DwWqDUNgnKV len=0 
' 0018     25 LABEL : Cell Value, String Constant - EFJQXqyrrd len=0 
' 0018     27 LABEL : Cell Value, String Constant - EKPxqviJMcUy len=0 
' 0018     24 LABEL : Cell Value, String Constant - EtXTaGSbP len=0 
' 0018     20 LABEL : Cell Value, String Constant - gCIMS len=0 
' 0018     22 LABEL : Cell Value, String Constant - JydrLXm len=0 
' 0018     20 LABEL : Cell Value, String Constant - LudIS len=0 
' 0018     22 LABEL : Cell Value, String Constant - MJWAIGR len=0 
' 0018     23 LABEL : Cell Value, String Constant - mQWrSdAe len=0 
' 0018     23 LABEL : Cell Value, String Constant - OQTeiCnO len=0 
' 0018     24 LABEL : Cell Value, String Constant - QjhMKbfst len=0 
' 0018     24 LABEL : Cell Value, String Constant - RqMcQjAeu len=0 
' 0018     22 LABEL : Cell Value, String Constant - SgTJGDH len=0 
' 0018     20 LABEL : Cell Value, String Constant - TDoyl len=0 
' 0018     20 LABEL : Cell Value, String Constant - tLgfE len=0 
' 0018     20 LABEL : Cell Value, String Constant - vNoev len=0 
' 0018     21 LABEL : Cell Value, String Constant - vTLYRY len=0 
' 0018     22 LABEL : Cell Value, String Constant - WlcGElQ len=0 
' 0018     23 LABEL : Cell Value, String Constant - yqUDErFW 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 LABELSST : Cel
... (truncated)

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