Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 44cebef95159e3ed…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:43:13 Authoring application: Microsoft Excel First seen: 2021-09-16
MD5: 63e0e016f98db40935da31f09fe462a1 SHA-1: 1a3c5707d92f1c43f0740aca6b7ce1fbbe001dc5 SHA-256: 44cebef95159e3ed9498d5b45e93f5fe1957cd4a6290ecd10426e950c2d0a0e2
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 document detected with critical heuristics for an Auto_Open defined name and dangerous formula APIs. The presence of an Auto_Open entry indicates that the macro will execute automatically when the workbook is opened, facilitating the execution of malicious code. The document body contains a large amount of seemingly random characters, suggesting it may be obfuscated or contain embedded data for the macro to process.

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) 6454 bytes
SHA-256: 5d88fb3b440c4f79cb3a420b17b1d417342b2c61801b82a674ab6f9e81808be9
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 -  kEcsM
' 0018     22 LABEL : Cell Value, String Constant - AMuoFJn len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I183 
' 0018     22 LABEL : Cell Value, String Constant - DGvrKYZ len=0 
' 0018     25 LABEL : Cell Value, String Constant - dvjWvpsgfR len=0 
' 0018     22 LABEL : Cell Value, String Constant - EiLkXmY len=0 
' 0018     25 LABEL : Cell Value, String Constant - FxnjNoOReV len=0 
' 0018     27 LABEL : Cell Value, String Constant - gDeEmmqsKnwm len=0 
' 0018     23 LABEL : Cell Value, String Constant - HiAWQXeG len=0 
' 0018     20 LABEL : Cell Value, String Constant - HoMcW len=0 
' 0018     25 LABEL : Cell Value, String Constant - IgaQKNdmwq len=0 
' 0018     22 LABEL : Cell Value, String Constant - KKvRKXi len=0 
' 0018     20 LABEL : Cell Value, String Constant - pxZVb len=0 
' 0018     25 LABEL : Cell Value, String Constant - qDURrxTzgc len=0 
' 0018     23 LABEL : Cell Value, String Constant - rAqtZZxq len=0 
' 0018     25 LABEL : Cell Value, String Constant - RgfjjYFlGB len=0 
' 0018     24 LABEL : Cell Value, String Constant - rzHjlgjdf len=0 
' 0018     20 LABEL : Cell Value, String Constant - Vveno len=0 
' 0018     27 LABEL : Cell Value, String Constant - wGmznSRlroNZ len=0 
' 0018     22 LABEL : Cell Value, String Constant - wyUtlnd len=0 
' 0018     20 LABEL : Cell Value, String Constant - ZeZzp len=0 
' 0018     26 LABEL : Cell Value, String Constant - ZiWiKgIBhvX 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 LA
... (truncated)

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