Merge pull request #54 from cisagov/automate-hash-scans

Automate hash scans

extras/ioc_hash_scan.sh

@@ -0,0 +1,184 @@
+#!/bin/bash
+#
+# This script will scan AWS instances for occurrences of IOC hashes listed in
+# the blob at src/ioc_scan/ioc_scanner.py
+#
+# The filename specified in the first argument
+# (instance-list-file) should contain a list of instance id strings, one per line.
+#
+# The following environment variables must be set:
+# AWS_SHARED_CREDENTIALS_FILE
+# AWS_REGION
+# AWS_PROFILE
+#
+# Usage: ./ioc_hash_scan.sh instance-list-file
+#
+# This script assumes that it exists in the ioc-scanner/extras/ directory.
+# If it does not, please edit the variable $pydir to point to
+# the directory containing ioc_scanner.py
+
+set -o nounset
+set -o errexit
+set -o pipefail
+
+# Directory path of the ioc_scanner.py file
+pydir="../src/ioc_scan/"
+
+if [ $# -eq 0 ] || [ "$1" = "-h" ] || [ "$1" = "--help" ] || [ $# -gt 1 ]; then
+  echo Usage: "$0" instance-list-file
+  exit 1
+fi
+
+# Check if instance list file exists.
+if [ ! -f "$1" ]; then
+  echo Instance List file "$1" does not exist - exiting.
+  exit 1
+fi
+
+# Check if environment variables are set
+CRED=$(env | grep AWS_SHARED_CREDENTIALS_FILE)
+REG=$(env | grep AWS_REGION)
+PROF=$(env | grep AWS_PROFILE)
+[[ -z "$CRED" ]] && {
+  echo "AWS_SHARED_CREDENTIALS_FILE environment variable is not set."
+  exit 1
+}
+[[ -z "$REG" ]] && {
+  echo "AWS_REGION environment variable is not set."
+  exit 1
+}
+[[ -z "$PROF" ]] && {
+  echo "AWS_PROFILE environment variable is not set."
+  exit 1
+}
+
+# Read instance id strings from file.  [[ -n "$line" ]] handles the case where
+# the last line doesn't end with a newline.
+serverList=()
+while IFS= read -r line || [[ -n "$line" ]]; do
+  serverList+=("$line")
+done < "$1"
+
+if [ ${#serverList[@]} -eq 0 ]; then
+  echo No instances found in "$1" - exiting.
+  exit 1
+fi
+
+today=$(date +%Y-%m-%d)
+logfile="$HOME/$today-ioc-scanner-hashscan.log"
+
+# Suppress some verbose stdout.
+exec > >(grep --invert-match 'Starting\|Exiting')
+
+## FUNCTIONS
+function getOSType() {
+  OSNAME=$(aws ssm start-session --target="$i" \
+    --document=AWS-StartInteractiveCommand \
+    --parameters="command=cat /etc/os-release | grep --extended-regexp ^NAME=" \
+    --output text)
+  echo "$OSNAME" | grep NAME | cut -d'"' -f2 | cut -d' ' -f1
+}
+
+function getHost() {
+  HOST=$(aws ssm start-session --target="$i" \
+    --document=AWS-StartNonInteractiveCommand \
+    --parameters="command=hostname" \
+    --output text)
+  echo "$HOST" | grep --invert-match "session" | sed '/^$/d'
+}
+
+function portForward() {
+  aws ssm start-session --target="$i" \
+    --document=AWS-StartPortForwardingSession --parameters="localPortNumber=5555,portNumber=6666"
+}
+
+function installNC() {
+  if [[ "$OS" == "Debian" ]]; then
+    aws ssm start-session --target="$i" \
+      --document=AWS-StartInteractiveCommand \
+      --parameters="command='sudo apt-get --yes install netcat'"
+  else
+    aws ssm start-session --target="$i" \
+      --document=AWS-StartInteractiveCommand \
+      --parameters="command='sudo dnf --assumeyes install netcat'"
+  fi
+}
+
+function startListen() {
+  if [[ "$OS" == "Debian" ]]; then
+    aws ssm start-session --target="$i" \
+      --document=AWS-StartInteractiveCommand \
+      --parameters="command='cd ~/src/ioc_scan; nc -l -p 6666 | tar --extract --gzip --file -'"
+  else
+    aws ssm start-session --target="$i" \
+      --document=AWS-StartInteractiveCommand \
+      --parameters="command='cd ~/src/ioc_scan; nc -l 6666 | tar --extract --gzip --file -'"
+  fi
+}
+
+function getSessionID() {
+  SID=$(grep "Connection accepted for session" "$logfile" | tail --lines=1)
+  echo "$SID" | cut -d'[' -f 2 | cut -d']' -f 1
+}
+
+## MAIN SCRIPT
+echo "IOC Hash Scan - $today-$(date +%H:%M:%S)" > "$logfile"
+
+for i in "${serverList[@]}"; do
+  OS="$(getOSType)"
+  if [[ "$OS" != "Debian" && "$OS" != "Fedora" ]]; then
+    echo "Instance $i is running an operating system ($OS) that is not supported by this script."
+    echo "Currently only Debian and Fedora are supported - exiting."
+    exit 1
+  fi
+
+  instanceName=$(getHost)
+
+  echo "Beginning scan of instance $i -- $instanceName" | tee -a "$logfile"
+
+  # Start Port Forwarding
+  echo "Beginning port forwarding (local port 5555 to remote port 6666)"
+  portForward &
+
+  # Create ~/src/ioc_scan directory on Instance
+  echo "Verifying ~/src/ioc_scan directory on $instanceName"
+  aws ssm start-session --target="$i" \
+    --document=AWS-StartInteractiveCommand \
+    --parameters="command='if [ ! -d ~/src/ioc_scan ]; then mkdir --parents ~/src/ioc_scan; fi'"
+
+  #Install netcat and start listening on port 6666
+  echo "Verifying netcat on $instanceName"
+  installNC
+  echo "Begin listening on $instanceName"
+  startListen &
+
+  # Copy latest ioc_scanner.py to target instance
+  curdir=$(pwd)
+  cd "$pydir" || exit
+
+  echo "Upload lastest ioc_scanner.py to $instanceName"
+  tar --create --no-xattrs --gzip --file - ./ioc_scanner.py | nc localhost 5555
+
+  cd "$curdir" || exit
+
+  # Run ioc_scanner.py on target instance
+  echo "Scan $instanceName for IOC Hashes"
+  aws ssm start-session --target="$i" \
+    --document=AWS-StartInteractiveCommand \
+    --parameters="command=python3 ~/src/ioc_scan/ioc_scanner.py" >> "$logfile"
+
+  # Terminate session so we can do this again on the next instance.
+  id=$(getSessionID)
+  aws ssm terminate-session --session-id="$id"
+
+  echo "------------------------------------------------------------------------" | tee -a "$logfile"
+done
+
+##clean up log output for readability
+while grep --quiet --ignore-case "session" "$logfile"; do
+  sed -i '' '/session/d' "$logfile"
+done
+
+sed -i '' 'N;/^\n$/D;P;D;' "$logfile"
+
+echo "Scan log may be found at: $logfile"