exchange-owa-attack

Exchange/OWA Attack Skill

Exchange Outlook Web Access reconnaissance covering endpoint mapping, NTLM Type-2 metadata, authentication controls, and version evidence. Password or lockout testing requires explicit authorization and approved identities.

When to Use

• Target has owa., mail., webmail., exchange., or autodiscover. subdomains.
• crt.sh reveals Exchange-related SAN names (mail.domain.com, autodiscover.domain.com).
• Port 443 returns NTLM WWW-Authenticate: Negotiate or WWW-Authenticate: NTLM.
• After subdomain-enumeration discovers mail-related hosts.
• After port-service-discovery finds HTTPS on port 443 with Exchange fingerprints.

Prerequisites

• terminal with curl, python3.
• Target Exchange/OWA URL.
• For password spray: list of usernames (from recon) and password candidates.

How to Run

# Quick Exchange detection
curl --max-time 30 --connect-timeout 10 -skI "https://TARGET/owa/" | grep -iE "x-owa-version|x-feserver|exchange|microsoft"

# NTLM challenge capture (AD domain leak)
curl --max-time 30 --connect-timeout 10 -skI "https://TARGET/owa/" -H "Authorization: Negotiate TlRMTVNTUAABAAAAB4IIogAAAAAAAAAAAAAAAAAAAAAGAbEdAAAADw==" | grep -i "www-authenticate"

Quick Reference

Procedure

Phase 1 — Exchange Detection & Fingerprinting

TARGET="$1"
OUTDIR="$OUTDIR/exchange"
mkdir -p "$OUTDIR"

echo "[*] Exchange detection on $TARGET"

# OWA probe
OWA_RESP=$(curl -skI --max-time 10 --connect-timeout 10 "https://$TARGET/owa/" 2>/dev/null)
echo "$OWA_RESP" > "$OUTDIR/owa_headers.txt"

# Version extraction
X_OWA=$(echo "$OWA_RESP" | grep -i "x-owa-version" | sed 's/.*: //')
X_FE=$(echo "$OWA_RESP" | grep -i "x-feserver" | sed 's/.*: //')

if [[ -n "$X_OWA" ]]; then
  echo "[+] Exchange confirmed — OWA Version: $X_OWA"
  echo "  Frontend server: ${X_FE:-unknown}"

  # Map version to CU
  # 15.1.x = Exchange 2016, 15.2.x = Exchange 2019
  MAJOR=$(echo "$X_OWA" | cut -d. -f1-2)
  if [[ "$MAJOR" == "15.1" ]]; then
    echo "  Product: Exchange 2016"
  elif [[ "$MAJOR" == "15.2" ]]; then
    echo "  Product: Exchange 2019"
  fi
else
  echo "[-] No OWA version header — may not be Exchange"
fi

# Key endpoints probe
declare -A EX_ENDPOINTS
EX_ENDPOINTS["/owa/auth/logon.aspx"]="Login page"
EX_ENDPOINTS["/ecp/"]="Exchange Control Panel (admin)"
EX_ENDPOINTS["/ews/exchange.asmx"]="Exchange Web Services (SOAP)"
EX_ENDPOINTS["/autodiscover/autodiscover.xml"]="Autodiscover"
EX_ENDPOINTS["/mapi/emsmdb/"]="MAPI over HTTP"
EX_ENDPOINTS["/Microsoft-Server-ActiveSync/"]="ActiveSync"
EX_ENDPOINTS["/rpc/rpcproxy.dll"]="Outlook Anywhere"
EX_ENDPOINTS["/owa/healthcheck.htm"]="Health check"

echo ""
echo "[*] Endpoint probe:"
for ep in "${!EX_ENDPOINTS[@]}"; do
  code=$(curl -sk -o /dev/null -w "%{http_code}" --max-time 5 --connect-timeout 5 "https://$TARGET$ep")
  [[ "$code" == "200" ]] && echo "  [OPEN] $ep — ${EX_ENDPOINTS[$ep]}"
  [[ "$code" == "302" ]] && echo "  [REDIR] $ep — ${EX_ENDPOINTS[$ep]}"
  [[ "$code" == "401" ]] && echo "  [AUTH] $ep — ${EX_ENDPOINTS[$ep]}"
done