Intermediate - RE3 - We Just Got A Letter! Wonder who it’s from?!150
If you want to send spaceage mail, it gets pretty confusing. However, you might be able to figure out what is going on here with this mail we are trying to send. Take a look!
It looks like there is some base64 going on, but it isn’t that easy right?
    ${01010100100111100} = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('UwBVAGQARgBlADAASgA1AGMAbQBOAG8AWAAwAE4AeQBNADIARgAwAFoAVwBSAGYAZABHAGcAeABKAEgAMAA9AA=='))) ${01010100100111100} = [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes(${01010100100111100})) ${01101101101101110} = @{ From = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('agBvAGgAbgBAAGQAcwB1AC4AZQBkAHUA'))) To = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('bQBhAHIAaQBlAGwAQABkAHMAdQAuAGUAZAB1AA=='))) Subject = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('VQBuAHMAcABvAGsAZQBuACAAVAByAHUAdABoAHMA'))) Body = $([System.Text.Encoding]::Unicode.GetString([System.Convert]::FromBase64String("$($([System.Text.Encoding]::Unicode.GetString([System.Convert]::FromBase64String($ExecutionContext.InvokeCommand.ExpandString([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('JAB7ADAAMQAwADEAMAAxADAAMAAxADAAMAAxADEAMQAxADAAMAB9AA==')))))))"))) SmtpServer = $([Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('cwBtAHQAcAAuAGcAbQBhAGkAbAAuAGMAbwBtAA=='))) } Send-MailMessage @01101101101101110
Flag format: IGE{XXXXX_XXXXXXX_XXX}
ctf@kali:/ige# echo 'UwBVAGQARgBlADAASgA1AGMAbQBOAG8AWAAwAE4AeQBNADIARgAwAFoAVwBSAGYAZABHAGcAeABKAEgAMAA9AA==' | base64 -dSUdFe0J5cmNoX0NyM2F0ZWRfdGgxJH0=ctf@kali:/ige# ctf@kali:/ige# echo 'SUdFe0J5cmNoX0NyM2F0ZWRfdGgxJH0=' | base64 -dIGE{Byrch_Cr3ated_th1$}ctf@kali:/ige# 
flag: IGE{Byrch_Cr3ated_th1$}