Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 bf5c18b998f125e1…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:40:41 Authoring application: Microsoft Excel First seen: 2020-12-25
MD5: b4a5fed84f95beec4670e6cc663554de SHA-1: 6b7cc8162daca4bedd0d6350e51b20221f8adfb6 SHA-256: bf5c18b998f125e1c1cb5be6fae46e9c2c15125de4c134b3a0449102ecd061e4
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 defined name, which is a critical indicator of malicious intent. This technique allows for the execution of arbitrary code upon opening the workbook, likely to download and execute a second-stage payload. The presence of dangerous formula APIs further supports this assessment.

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) 6720 bytes
SHA-256: 29174cffae57909b6c7949319852f31a1a6fe32b7ae40f9a90eafa8515a9ea82
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 -  SAROYPd
' 0018     22 LABEL : Cell Value, String Constant - aBPLZBB len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C149 
' 0018     27 LABEL : Cell Value, String Constant - AzFdErxnFdge len=0 
' 0018     21 LABEL : Cell Value, String Constant - CYAOCv len=0 
' 0018     26 LABEL : Cell Value, String Constant - DuwoIWpQEmi len=0 
' 0018     23 LABEL : Cell Value, String Constant - EEdczqIi len=0 
' 0018     25 LABEL : Cell Value, String Constant - fDmCMDXAJw len=0 
' 0018     23 LABEL : Cell Value, String Constant - FxFsQbIp len=0 
' 0018     21 LABEL : Cell Value, String Constant - imHZQP len=0 
' 0018     24 LABEL : Cell Value, String Constant - kXXvGtuUQ len=0 
' 0018     20 LABEL : Cell Value, String Constant - LUWGf len=0 
' 0018     23 LABEL : Cell Value, String Constant - MqHMalRY len=0 
' 0018     26 LABEL : Cell Value, String Constant - MyBqicmoRDs len=0 
' 0018     21 LABEL : Cell Value, String Constant - nttTov len=0 
' 0018     24 LABEL : Cell Value, String Constant - perjpCGCr len=0 
' 0018     21 LABEL : Cell Value, String Constant - QeqhYS len=0 
' 0018     21 LABEL : Cell Value, String Constant - RBUcsZ len=0 
' 0018     27 LABEL : Cell Value, String Constant - RPMYHerDwpvL len=0 
' 0018     24 LABEL : Cell Value, String Constant - uhEHUpFHg len=0 
' 0018     26 LABEL : Cell Value, String Constant - WUdkBZrYzTN len=0 
' 0018     26 LABEL : Cell Value, String Constant - YFROsfMpCut 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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