Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0ef3cdfd64e089d1…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:38:51 Authoring application: Microsoft Excel First seen: 2021-06-28
MD5: d6dcfb92663114819ea0ef106f280fd8 SHA-1: 3c29634173afa3cd7139a030101e8481ebafec82 SHA-256: 0ef3cdfd64e089d12f8eba385ba674c53bb9537056d6dae044533ed14e2ad333
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 (XLM) macros, specifically triggering an Auto_Open function. This indicates an attempt to execute arbitrary code upon opening the document. The presence of dangerous formula APIs like RUN suggests the macro is designed to download and execute a secondary payload, a common technique for initial compromise.

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) 6533 bytes
SHA-256: 3e29d345a8e6f3b698daa4dde3a83489dfef88d46a2539fd6b7fc2fd2d97eaf8
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 -  kJFDu
' 0018     25 LABEL : Cell Value, String Constant - aaZsPUNmmH len=0 
' 0018     27 LABEL : Cell Value, String Constant - AlUdIoahzroZ len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C144 
' 0018     27 LABEL : Cell Value, String Constant - CkvstjALhElF len=0 
' 0018     23 LABEL : Cell Value, String Constant - dRyASRva len=0 
' 0018     21 LABEL : Cell Value, String Constant - edUDGh len=0 
' 0018     21 LABEL : Cell Value, String Constant - gFJPFt len=0 
' 0018     26 LABEL : Cell Value, String Constant - GhMLTyyAMQB len=0 
' 0018     22 LABEL : Cell Value, String Constant - HfaZgYZ len=0 
' 0018     27 LABEL : Cell Value, String Constant - IlqTePCqUfKN len=0 
' 0018     25 LABEL : Cell Value, String Constant - IwvPdeCUOO len=0 
' 0018     24 LABEL : Cell Value, String Constant - KXSzjaUqS len=0 
' 0018     20 LABEL : Cell Value, String Constant - miIum len=0 
' 0018     21 LABEL : Cell Value, String Constant - pmxBbx len=0 
' 0018     25 LABEL : Cell Value, String Constant - suBsXvfBNL len=0 
' 0018     27 LABEL : Cell Value, String Constant - TSYErSXfNwnb len=0 
' 0018     23 LABEL : Cell Value, String Constant - uYPUVyeQ len=0 
' 0018     20 LABEL : Cell Value, String Constant - vDDis len=0 
' 0018     23 LABEL : Cell Value, String Constant - VfOqZSvC len=0 
' 0018     26 LABEL : Cell Value, String Constant - ZgFJisHpnkm len=0 
' 0018     26 LABEL : Cell Value, String Constant - zXiNKHyxOwD 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
' 
... (truncated)

Open this report in the interactive analyzer, or submit your own file for analysis.