Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b5f0a4303381344b…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:41:38 Authoring application: Microsoft Excel First seen: 2021-06-30
MD5: c7597876c1ddd75e69e8a785a2d04f2d SHA-1: dc24022833bbfb18288d36931b39d4a6ca2c3510 SHA-256: b5f0a4303381344b197922cffa062132839737b6af46783988febbf2eac042bb
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 function, which is a known method for executing malicious code within older Excel versions. The critical heuristics indicate the presence of dangerous formula APIs, suggesting the macro is designed to perform actions beyond typical spreadsheet operations. Without further deobfuscation or dynamic analysis, the exact payload and its target are unknown, leading to an 'unknown family' classification.

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) 6621 bytes
SHA-256: b1b2f0c0453512fbef7f84a59f4faa8f91db2588f5f408c86e0ca517e252eb50
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  UAtpLrFnE
' 0018     24 LABEL : Cell Value, String Constant - AaSChrzTq len=0 
' 0018     21 LABEL : Cell Value, String Constant - AcgCpk len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G164 
' 0018     26 LABEL : Cell Value, String Constant - dIjjurVJVID len=0 
' 0018     21 LABEL : Cell Value, String Constant - DMDrhM len=0 
' 0018     23 LABEL : Cell Value, String Constant - HKTiLZrH len=0 
' 0018     21 LABEL : Cell Value, String Constant - IfbQrK len=0 
' 0018     23 LABEL : Cell Value, String Constant - iVWcWVHH len=0 
' 0018     21 LABEL : Cell Value, String Constant - izTOCr len=0 
' 0018     24 LABEL : Cell Value, String Constant - jHVirXzYJ len=0 
' 0018     25 LABEL : Cell Value, String Constant - JUqbbwwWXp len=0 
' 0018     22 LABEL : Cell Value, String Constant - jursQQl len=0 
' 0018     23 LABEL : Cell Value, String Constant - KrtVRgbS len=0 
' 0018     23 LABEL : Cell Value, String Constant - kSOklilj len=0 
' 0018     27 LABEL : Cell Value, String Constant - pfqLiuyOtTPY len=0 
' 0018     21 LABEL : Cell Value, String Constant - SNQaAe len=0 
' 0018     22 LABEL : Cell Value, String Constant - SoGKQsO len=0 
' 0018     25 LABEL : Cell Value, String Constant - YiirAvLbKe len=0 
' 0018     24 LABEL : Cell Value, String Constant - YJhJkMfpy len=0 
' 0018     22 LABEL : Cell Value, String Constant - ykNwLxn len=0 
' 0018     27 LABEL : Cell Value, String Constant - ZDafPQnqtTHX 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     1
... (truncated)

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