#Requires -Version 5.1
<#
    JbTecWiz Support Centre -- generated fix script

    Fault : Files renamed with an unfamiliar extension and a ransom note
    Fix   : Contain it -- network first, power last
    Source: https://jbtecwiz.com/support/win-sec-ransomware

    Run as     : The affected machines
    Expect     : 30 minutes
    Risk       : high
    Reversible : NO -- read the undo note below before running

    WHEN THIS IS THE RIGHT FIX
    Encryption is in progress. Minutes matter and the order of these steps
    matters.

    HOW TO UNDO IT
    None -- this is containment, not repair.

    This script walks the fix one step at a time and asks before each
    one. Steps with no command are things you do yourself -- it prints
    those and waits. Run with -DryRun to print without executing.

    --------------------------------------------------------------------
    NO WARRANTY - USE AT YOUR OWN RISK

    This script is provided by JbTecWiz as-is and with no warranty of any
    kind, express or implied. You run it entirely at your own risk.

    JbTecWiz accepts no liability for any loss or damage arising from its
    use, including but not limited to data loss, downtime, or configuration
    changes that turn out to be wrong for your system.

    You are responsible for reading this script before running it, for
    satisfying yourself that it suits the machine in front of you, and for
    having a working backup first. Some steps cannot be undone.
    --------------------------------------------------------------------
#>

[CmdletBinding()]
param(
    # Print every step and command without running anything.
    [switch]$DryRun,
    # Do not ask before each step. Read the script first if you use this.
    [switch]$Unattended
)

$ErrorActionPreference = 'Stop'
$script:Failed = 0

function Write-Rule { param([string]$Text)
    Write-Host ''
    Write-Host ('-' * 70) -ForegroundColor DarkGray
    if ($Text) { Write-Host $Text -ForegroundColor Cyan }
}

function Show-Prose { param([string]$Text, [string]$Colour = "Gray")
    if (-not $Text) { return }
    $words = $Text -split "\s+"; $line = "  "
    foreach ($w in $words) {
        if (($line.Length + $w.Length) -gt 74) { Write-Host $line -ForegroundColor $Colour; $line = "  " }
        $line += "$w "
    }
    if ($line.Trim()) { Write-Host $line -ForegroundColor $Colour }
}

function Invoke-Step {
    param(
        [int]$Number, [string]$Do, [string]$Why,
        [scriptblock]$Command, [switch]$Manual, [string]$Shell = "powershell"
    )
    Write-Rule "  Step $Number of 5"
    Show-Prose $Do "White"
    if ($Why) { Write-Host ""; Show-Prose $Why "DarkGray" }

    if ($Manual) {
        Write-Host ''
        Write-Host '  -> Do this yourself, then press Enter to carry on.' -ForegroundColor Yellow
        if (-not $Unattended -and -not $DryRun) { [void](Read-Host) }
        return
    }

    Write-Host ''
    foreach ($l in ($Command.ToString().Trim() -split "`n")) {
        Write-Host ("    " + $l.Trim()) -ForegroundColor Green
    }
    Write-Host ''

    if ($DryRun) { Write-Host "  (dry run -- not executed)" -ForegroundColor DarkGray; return }
    if (-not $Unattended) {
        $a = Read-Host "  Run this step? [Y]es / [S]kip / [Q]uit"
        if ($a -match "^[Qq]") { Write-Host "  Stopped at your request."; exit 0 }
        if ($a -match "^[Ss]") { Write-Host "  Skipped." -ForegroundColor DarkGray; return }
    }
    try { & $Command }
    catch {
        $script:Failed++
        Write-Host ("  Step $Number failed: " + $_.Exception.Message) -ForegroundColor Red
        Show-Prose "The rest of the fix may depend on this. Read the write-up before carrying on." "Red"
        if (-not $Unattended) {
            $c = Read-Host "  Carry on anyway? [y/N]"
            if ($c -notmatch "^[Yy]") { exit 1 }
        }
    }
}

Write-Rule
Write-Host '  Files renamed with an unfamiliar extension and a ransom note' -ForegroundColor White
Write-Host '  Contain it -- network first, power last' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: high   NOT REVERSIBLE   30 minutes' -ForegroundColor Yellow
Write-Host ''
Show-Prose 'Undo: None -- this is containment, not repair.' 'Yellow'
Write-Host ''
Show-Prose 'No warranty. Use at your own risk - JbTecWiz accepts no liability. Read it before you run it, and have a backup.' 'DarkYellow'
Write-Rule

if (-not $Unattended -and -not $DryRun) {
    $go = Read-Host '  Ready? [y/N]'
    if ($go -notmatch "^[Yy]") { Write-Host "  Nothing was changed."; exit 0 }
}

Invoke-Step -Number 1 -Do 'Disconnect the affected machines from the network -- unplug the cable, disable the Wi-Fi. Do this before anything else.' -Why 'Isolating the machine stops it reaching more shares. It is the single most valuable action available and it costs seconds.' -Manual

Invoke-Step -Number 2 -Do 'Do not power the machine off if it can be avoided. The encryption key is sometimes still in memory, and a memory capture is occasionally the difference between recovery and not.' -Why 'This is the step most people get wrong. Pulling the power feels decisive and destroys volatile evidence -- and sometimes the key itself -- for no gain over disconnecting the network.' -Manual

Invoke-Step -Number 3 -Do 'Disconnect backups and any external drive immediately, before checking whether they are affected.' -Manual

Invoke-Step -Number 4 -Do 'On the file server, stop the shares to halt further damage while you assess.' -Command {
    Get-SmbSession | Format-Table ClientComputerName,ClientUserName,NumOpens
    Get-SmbShare | Where-Object Name -notin 'ADMIN$','IPC$','C$' | Set-SmbShare -Force -ErrorAction SilentlyContinue
}

Invoke-Step -Number 5 -Do 'Identify the account doing it -- the SMB session list above usually names the machine and user within seconds.' -Manual

Write-Rule "  Confirm it worked"
Show-Prose 'No further files are changing on the shares, and the affected machines are off the network.' 'White'

Write-Rule
if ($script:Failed -gt 0) {
    Write-Host ("  Finished with " + $script:Failed + " failed step(s).") -ForegroundColor Yellow
    Show-Prose 'Read the full write-up at https://jbtecwiz.com/support/win-sec-ransomware' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: None -- this is containment, not repair.' 'DarkGray'
Write-Rule