Securing AWS with HIDS. Gaurav Harsola Mayank Gaikwad

Transcription

1 Securing AWS with HIDS» Gaurav Harsola Mayank Gaikwad

2 IDS What? Why? How?

3 Intrusion Detection System An IDS is a software application that monitors network or system activities for malicious activities.

4 An IDS is not a Firewall

5 NIDS and HIDS HIDS A host-based intrusion detection system (HIDS) is a system that run on individual hosts and monitors a computer system Detect an intrusion and/or misuse, and responds by logging the activity It is an agent that monitors and analyzes whether anything or anyone, whether internal or external, has bypass the system s security policy. Tools like : Samhain, Ossec NIDS NIDS is placed within the network to monitor traffic to and from all devices on network NIDS scan all inbound and outbound traffic NIDS tools operate by inspecting traffic that occurs between hosts. Various Tools like Snort, Suricata, Bro, Kismet

6 Available HIDS OSSEC: OpenSource Wazuh : OpenSource, Wrapper Over OSSEC with API, ELK, And Signature DB AlianVault: Licenced, USM (Unified Security Management) is based OSSEC MicroTrend: Licenced AlertLogic: Licenced,

7 OSSEC? OSSEC is an Open Source Host-based Intrusion Detection System. Key Features: Log analysis File Integrity checking (Unix and Windows) Registry Integrity checking (Windows) Host-based anomaly detection (for Unix rootkit detection) Active response Ossec is mainly used for three things: See what is going on Stop brute-force attacks ( ftp, ssh, web )

8 Ossec Benefits Open-Source Log Analysis Easy to install Easy to customize (rules and config in XML format) Scalable (client/server architecture) High Availability (Can have multiple OSSEC Server) Multi-Platform Ossec comes with existing standard decoders /rules which analyse our logs like telnetd, Sudo, SSH, FTP etc PCI DSS Compliance at some extent.

9 Ossec Agent/Server Flow

10 Ossec Internal Components Analysisd Does all the analysis (main process) Remoted Receives remote logs from agents Logcollector Reads log files (syslog, Flat files, Windows event log, IIS, etc) Agentd Forwards logs to the server Maild Sends alerts Execd Executes the active responses Monitord Monitors agent status, compresses and signs log files, etc Integratord - Integrating OSSEC with Slack and PagerDuty Authd - Daemon will automatically add an agent to an OSSEC manager

11 Wazuh Wazuh, A wrapper over OSSEC that provide additonal fucntionality like Restful API, ELK integration.

12 Ossec Server/Client Installtion Firstly, Install necessary package required sudo apt-get install gcc make git sudo apt-get install libssl-dev After this clone our Github repository mkdir ossec_tmp && cd ossec_tmp git clone -b stable cd ossec-wazuh sudo./install.sh Choose server for server installation and agent for client installation when being asked about the installation type and answer the rest of questions as desired. Once installed, you can start your OSSEC manager running: sudo /var/ossec/bin/ossec-control start Check the service : ps aux grep ossec

13 Connect Client with Server After Setting up agent we need to Connect it with OSSEC-Server. To make life easier, OSSEC added a new daemon on the server, called ossec-authd. it is a daemon you run on the server when you deploy your agent; it will populate your agents key; when you have finished to deploy, you stop it. Once the keys are created, you can start the ossec-authd: /var/ossec/bin/ossec-authd -p 1515 Setting up the agents On the agents, the work is minimal. All you have to do is to run the following command: /var/ossec/bin/agent-auth -m <ServerIP> -p A <agent-name> That s it. The keys are now exchanged and you can start your agent. sudo /var/ossec/bin/ossec-control start

14 Sample of Alerts.json

15 Ossec Integration with ELK OSSEC HIDS integration with ELK Stack provides a real-time alerts managemnet console, as well as flexible way to store data for as long as needed.

16 Ossec Directory Structure

17 Internal log flow

18 Log pre-decoding (1) Decoding of a SSHD message: After pre-decoding by OSSEC? time/date -> Apr 14 17:32:06 hostname -> ubuntu program_name -> sshd log -> Accepted password for root from port...

19 Log Decoding (2) Process to identify key information from logs OSSEC comes with hundreds of decoders Generally we want to extract source ip, user name, id After Decode by OSSEC : time/date -> Apr 14 17:32:06 hostname -> ubuntu program_name -> sshd log -> Accepted password for root from port srcip -> user -> root

20 Writing decoders Writing a decoder. What it requires? sshd example: We want to extract the user name and source ip If program name was pre-decoded as sshd (remember predecoding?), try this regular expression

21 Log Rules Next step after decoding is to check the rules User-defined XML Very easy to write! Allows to match based on decoded information OSSEC comes with more than 400 rules by default! What it requires? A Rule id (any integer) A Level - from 0 (lowest) to 15 (highest) Level 0 is ignored, not alerted at all Pattern - anything from regex, to srcip, id, user, etc

22 Writing your own rules

23 PCI DSS Payment Card industry Data Security Standard. Visa, MasterCard and other card brands create common industry security requirements Intended to protect cardholders data wherever it resides compliance is mandated for all organization handling credit card data 12 Steps that we need to take to achieve PCI DSS compliance are Firewall, password, storage, Encrypt, anti-virus, uniquid, track and monitor etc OSSEC helps to implement PCI DSS by performing log analysis, file integrity checking, policy monitoring, intrusion detection, real-time alerting and active response.

24 Monitor AWS logs Cloudtrail pushes data to s3 bucket and then using python script we store that log on ossec server

25 Alerting and Notification Slack Integration: Integration of logs with slack and set alert level so that only particular message come in slack. <integration> <name>slack</name> <hook_url> <level>7</level> </integration> Integration: Integration with .Send granule alert based on the level/rulegroups/rule_id to different recipient. < _alerts> <group>sql_injection authentication_failed authentication_failures</group> <level>6</level> <format>sms</format> </ _alerts>

26 HIDS Implementation Testing Tested FTP, SSH brute force attack using HYDRA as penetration testing tool. Example: hydra -L /home/ubuntu/user.txt -P /home/ubuntu/pwd.txt -s 22 <IP> <servicename> -L file which contain list of username -P file which contain list of password service-name : it may be ssh,ftp,mysql,telnet -s port Number for service

27 Elasticsearch UI

28 Kibana UI

29 Thanks & Questions?