Major update to version 0.3

This commit is contained in:
Eric Conrad
2017-08-30 15:43:08 -04:00
committed by GitHub
parent 28e9686a23
commit 8c9bff9614

View File

@ -25,7 +25,7 @@ https://github.com/sans-blue-team/DeepBlueCLI
#>
# DeepBlueCLI 0.1 Beta
# DeepBlueCLI 0.3 Beta
# Eric Conrad, Backshore Communications, LLC
# deepblue <at> backshore <dot> net
# Twitter: @eric_conrad
@ -48,10 +48,10 @@ function Main {
$maxfailedlogons=100 # Alert after this many failed logons
# Get the events:
try{
$events = iex "Get-WinEvent -FilterHashtable $filter -ErrorAction Stop"
$events = iex "Get-WinEvent $filter -ErrorAction Stop"
}
catch {
Write-Host "Get-WinEvent -FilterHashtable $filter -ErrorAction Stop"
Write-Host "Get-WinEvent $filter -ErrorAction Stop"
Write-Host "Get-WinEvent error: " $_.Exception.Message "`n"
Write-Host "Exiting...`n"
exit
@ -177,11 +177,70 @@ function Main {
$output += (Check-Command $pscommand $minlength $regexes $whitelist 0)
}
}
# Ignoring PowerShell event 4014 for now, DeepBlueCLI currently detects its own strings, and hilarity ensures
#ElseIf ($event.id -eq 4104){
# $pscommand=$eventXML.Event.EventData.Data[2]."#text"
# $output += (Check-Command $pscommand 9999 $regexes $whitelist 0)
#}
ElseIf ($event.id -eq 4104){
# This section requires PowerShell command logging, which is not the default with
# event 4104 (logs the script block but not the command that launched it).
#
# Add the following to \Windows\System32\WindowsPowerShell\v1.0\profile.ps1
# $LogCommandHealthEvent = $true
# $LogCommandLifecycleEvent = $true
#
# See the following for more information:
#
# https://logrhythm.com/blog/powershell-command-line-logging/
# http://hackerhurricane.blogspot.com/2014/11/i-powershell-logging-what-everyone.html
#
# Thank you: @heinzarelli and @HackerHurricane
#
# The command's path is $eventxml.Event.EventData.Data[4]
# Blank path means it was run as a commandline. CLI parsing is *much* simpler than
# script parsing.
# This ignores scripts and grabs PowerShell CLIs
if (-not ($eventxml.Event.EventData.Data[4]."#text")){
$pscommand=$eventXML.Event.EventData.Data[2]."#text"
$output += (Check-Command $pscommand 500 $regexes $whitelist 0)
}
}
}
ElseIf ($logname -eq "Sysmon"){
#@{logname="Microsoft-Windows-Sysmon/Operational";id=1} | %{$_.Properties[11].Value}| sort -Unique
#get-winevent @{logname="Microsoft-Windows-Sysmon/Operational";id=1} | % {$_.Properties[11].Value}| Sort-Object -unique
#Get-WinEvent @{logname="Microsoft-Windows-Sysmon/Operational";id=7}|fl
# Check command lines
if ($event.id -eq 1){
#get-winevent @{logname="Microsoft-Windows-Sysmon/Operational";id=1} | % {$_.Properties[4].Value}
$commandline=$eventXML.Event.EventData.Data[4]."#text"
# Remove "Command Line: " from the $commandline
#$commandline= $commandline -Replace "^Command Line:",""
#$commandline
$output += (Check-Command $commandline $minlength $regexes $whitelist 0)
}
# Check for unsigned EXEs/DLLs:
ElseIf ($event.id -eq 7){
if ($eventXML.Event.EventData.Data[6]."#text" -eq "false"){
$image=$eventXML.Event.EventData.Data[3]."#text"
$imageload=$eventXML.Event.EventData.Data[4]."#text"
$hash=$eventXML.Event.EventData.Data[5]."#text"
$pscommand= " - Image: " + $image + "`r`n"
$pscommand+= " - ImageLoaded: " + $imageload + "`r`n"
#$pscommand+= " - Hash: " + $hash + "`r`n"
# Multiple hashes may be logged, we want SHA1. Remove everything through "SHA1="
$sha1= $hash -Replace "(?ms)^.*SHA1=",""
# Split the string on commas, grab field 0
$sha1=$sha1.Split(",")[0]
$hashfile=".\hashes\$sha1"
if (-not (Test-Path $hashfile)){
# Hash file doesn't exist, create it
$csv=$image+","+$imageload
$csv | Set-Content $hashfile
}
#$pscommand+= $eventXML.Event.EventData.Data[6]."#text" + "`r`n"
#$pscommand+= $eventXML.Event.EventData.Data[7]."#text" + "`r`n"
#$pscommand+= $eventXML.Event.EventData.Data[8]."#text" + "`r`n"
$output+= " Unsigned image:`r`n"
$output+= $pscommand
}
}
}
if ($output){
$event.TimeCreated
@ -209,6 +268,12 @@ function Check-Options($file, $log)
ElseIf ($log -eq "Application"){
$logname="Application"
}
ElseIf ($log -eq "Sysmon"){
$logname="Sysmon"
}
ElseIf ($log -eq "Powershell"){
$logname="Powershell"
}
Else{
write-host $log_error
exit 1
@ -234,7 +299,8 @@ function Check-Options($file, $log)
"System" {$logname="System"}
"Application" {$logname="Application"}
"Microsoft-Windows-AppLocker*" {$logname="Applocker"}
"Microsoft-Windows-PowerShell/Operational" {$logname="PowerShell"}
"Microsoft-Windows-PowerShell/Operational" {$logname="Powershell"}
"Microsoft-Windows-Sysmon/Operational" {$logname="Sysmon"}
default {"Logic error 3, should not reach here...";Exit 1}
}
}
@ -248,20 +314,22 @@ function Check-Options($file, $log)
function Create-Filter($file, $logname)
{
# Return the Get-Winevent -FilterHashtable filter
# Return the Get-Winevent filter
#
$sys_events="7030,7036,7045"
$sec_events="4688,4720,4728,4732,4625"
$app_events="2"
$applocker_events="8003,8004,8006,8007"
$powershell_events="4103"
$powershell_events="4103,4104"
$sysmon_events="1,7"
if ($file -ne ""){
switch ($logname){
"Security" {$filter="@{path=""$file"";ID=$sec_events}"}
"System" {$filter="@{path=""$file"";ID=$sys_events}"}
"Application" {$filter="@{path=""$file"";ID=$app_events}"}
"Applocker" {$filter="@{path=""$file"";ID=$applocker_events}"}
"PowerShell" {$filter="@{path=""$file"";ID=$powershell_events}"}
"Powershell" {$filter="@{path=""$file"";ID=$powershell_events}"}
"Sysmon" {$filter="@{path=""$file"";ID=$sysmon_events}"}
default {"Logic error 1, should not reach here...";Exit 1}
}
}
@ -271,7 +339,8 @@ function Create-Filter($file, $logname)
"System" {$filter="@{Logname=""System"";ID=$sys_events}"}
"Application" {$filter="@{Logname=""Application"";ID=$app_events}"}
"Applocker" {$filter="@{logname=""Microsoft-Windows-AppLocker"";ID=$applocker_events}"}
"PowerShell" {$filter="@{logname=""Microsoft-Windows-PowerShell/Operational"";ID=$powershell_events}"}
"Powershell" {$filter="@{logname=""Microsoft-Windows-PowerShell/Operational"";ID=$powershell_events}"}
"Sysmon" {$filter="@{logname=""Microsoft-Windows-Sysmon/Operational"";ID=$sysmon_events}"}
default {"Logic error 2, should not reach here...";Exit 1}
}
}
@ -317,6 +386,7 @@ function Check-Command($commandline,$minlength,$regexes,$whitelist,$servicecmd){
$decoded = [System.Text.Encoding]::Unicode.GetString([System.Convert]::FromBase64String($base64))
$text += " Decoded Base64:" + $decoded + "`n"
$text += " - Base64-encoded function`n"
$text += (Check-Obfu $decoded)
$text += (Check-Regex $decoded $regexes 0)
#foreach ($regex in $regexes){
# if ($regex.Type -eq 0) { # Image Path match
@ -351,20 +421,60 @@ function Check-Regex($string,$regexes,$type){
}
function Check-Obfu($string){
# Check how many "+" characters are in the command. Inspired by Invoke-Obfuscation: https://twitter.com/danielhbohannon/status/778268820242825216
# Check how many special characters are in the command. Inspired by Invoke-Obfuscation: https://twitter.com/danielhbohannon/status/778268820242825216
# There are many ways to do this, including regex. Need a way that doesn't kill the CPU. This works, but isn't super concise. There is probably a
# better way.
#
# Plan to add a loop to go through more characters.
$obfutext="" # Local variable for return output
$maxchars=25
# Remove the "+" characters
$string2 = $string -replace "\+"
#$obfuchars = "\+", "\'", "\}", "\{"
#foreach ($char in $obfuchars){
#
# I tried to loop through the characters (as the two commented lines above show, but
# hit problems of variable interpolation. I am probably making a simple mistake.
# If you can get the above loop working, please email deepblue at backshore dot net.
# I will repay in an adult beverage
#
# In the meantime, this is ugly, but works
$string2 = $string -replace "`'"
# Compare the length
if (($string.length - $string2.length) -gt $maxchars){
$obfutext += " - Possible command obfuscation: greater than $maxchars + characters`n"
$obfutext += " - Possible command obfuscation: greater than $maxchars ' characters`n"
}
$string2 = $string -replace "`{"
if (($string.length - $string2.length) -gt $maxchars){
$obfutext += " - Possible command obfuscation: greater than $maxchars { characters`n"
}
$string2 = $string -replace "`}"
if (($string.length - $string2.length) -gt $maxchars){
$obfutext += " - Possible command obfuscation: greater than $maxchars } characters`n"
}
$string2 = $string -replace ","
if (($string.length - $string2.length) -gt $maxchars){
$obfutext += " - Possible command obfuscation: greater than $maxchars , characters`n"
}
$string2 = $string -replace "!"
if (($string.length - $string2.length) -gt $maxchars){
$obfutext += " - Possible command obfuscation: greater than $maxchars ! characters`n"
}
$string2 = $string -replace "%"
if (($string.length - $string2.length) -gt $maxchars){
$obfutext += " - Possible command obfuscation: greater than $maxchars % characters`n"
}
$string2 = $string -replace "&"
if (($string.length - $string2.length) -gt $maxchars){
$obfutext += " - Possible command obfuscation: greater than $maxchars & characters`n"
}
$string2 = $string -replace ">"
if (($string.length - $string2.length) -gt $maxchars){
$obfutext += " - Possible command obfuscation: greater than $maxchars > characters`n"
}
$string2 = $string -replace "`""
if (($string.length - $string2.length) -gt $maxchars){
$obfutext += " - Possible command obfuscation: greater than $maxchars double quotes`n"
}
return $obfutext
#}
}
function Remove-Spaces($string){