The room: “Learn how to use Snort to detect real-time threats, analyse recorded traffic files and identify anomalies.”
https://tryhackme.com/room/snort
Task 2: Interactive Material and VM
2.1. Navigate to the Task-Exercises folder and run the command “./.easy.sh” and write the output
Since the file is hidden, it is prefixed with ” . ” before the name.
sudo ./.easy.sh
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Too Easy!
Task 3: Introduction to IDS/IPS
3.1. Which snort mode can help you stop the threats on a local machine?
HIPS
3.2. Which snort mode can help you detect threats on a local network?
NIDS
3.3. Which snort mode can help you detect the threats on a local machine?
HIDS
3.4. Which snort mode can help you stop the threats on a local network?
NIPS
3.5. Which snort mode works similar to NIPS mode?
NBA
3.6. According to the official description of the snort, what kind of NIPS is it?
full-blown
3.7. NBA training period is also known as …
baselining
Task 4: First Interaction with Snort
4.1. Run the Snort instance and check the build number.
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149
4.2. Test the current instance with “/etc/snort/snort.conf” file and check how many rules are loaded with the current build.
snort -c /etc/snort/snort.conf -T
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4151
4.3. Test the current instance with “/etc/snort/snortv2.conf” file and check how many rules are loaded with the current build.
snort -c /etc/snort/snortv2.conf -T
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1
Task 6: Operation Mode 2: Packet Logger Mode
6.1. Now, you should have the logs in the current directory. Navigate to folder “145.254.160.237”. What is the source port used to connect port 53?
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3009
6.2. Use snort.log.1640048004
Read the snort.log file with Snort; what is the IP ID of the 10th packet?
cd Desktop/Task-Exercises/Exercise-Files/TASK-6
sudo snort -r snort.log.1640048004 -n 10
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49313
6.3. Read the “snort.log.1640048004” file with Snort; what is the referer of the 4th packet?
sudo snort -r snort.log.1640048004 -X -n 10
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http://www.ethereal.com/development.html
6.4. Read the “snort.log.1640048004” file with Snort; what is the Ack number of the 8th packet?
sudo snort -r snort.log.1640048004 -n 8
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0x38AFFFF3
6.5.Read the “snort.log.1640048004” file with Snort; what is the number of the “TCP port 80” packets?
sudo snort -r snort.log.1640048004 'tcp and port 80'
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41
Task 7: Operation Mode 3: IDS/IPS
7.1. What is the number of the detected HTTP GET methods?
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2
Task 8: Operation Mode 4: PCAP Investigation
8.1. What is the number of the generated alerts?
cd Desktop/Task-Exercises/Exercise-Files/TASK-8/
sudo snort -c /etc/snort/snort.conf -A full -l . -r mx-1.pcap
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170
8.2. Keep reading the output. How many TCP Segments are Queued?
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18
8.3. Keep reading the output.How many “HTTP response headers” were extracted?
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3
8.4. What is the number of the generated alerts?
sudo snort -c /etc/snort/snortv2.conf -A full -l . -r mx-1.pcap
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68
8.5. What is the number of the generated alerts?
sudo snort -c /etc/snort/snort.conf -A full -l . -r mx-2.pcap
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340
8.6. Keep reading the output. What is the number of the detected TCP packets?
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82
8.7. What is the number of the generated alerts?
sudo snort -c /etc/snort/snort.conf -A full -l . --pcap-list="mx-2.pcap mx-3.pcap"
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1020
Task 9: Snort Rule Structure
9.1. Write a rule to filter IP ID “35369” and run it against the given pcap file. What is the request name of the detected packet?
alert icmp any any <> any any (msg:"IP ID"; id:35369; sid:1000001; rev:1;)
sudo snort -c local.rules -A full -l . -r task9.pcap
sudo snort -r snort.log.1680681113
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TIMESTAMP REQUEST
9.2. Create a rule to filter packets with Syn flag and run it against the given pcap file. What is the number of detected packets?
alert tcp any any <> any any (msg: "FLAG TEST"; flags:S; sid: 100001; rev:1;)
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1
9.3. Write a rule to filter packets with Push-Ack flags and run it against the given pcap file. What is the number of detected packets?
sudo rm snort.log.1680681590 snort.log.1680681113
sudo rm alert
alert tcp any any <> any any (msg: "FLAG TEST"; flags:PA; sid: 100001; rev:1;)
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216
9.4. Create a rule to filter packets with the same source and destination IP and run it against the given pcap file. What is the number of detected packets?
alert tcp any any <> any any (msg: "SAME-IP TEST"; sameip; sid: 100001; rev:1;)
alert udp any any <> any any (msg: "SAME-IP TEST"; sameip; sid: 100002; rev:1;)
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10
9.5. Case Example – An analyst modified an existing rule successfully. Which rule option must the analyst change after the implementation?
rev
a