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TryHackMe: Advent Of Cyber 2023 - Day 7

To take revenge for the company demoting him to regional manager during the acquisition, Tracy McGreedy installed the CrypTOYminer, a malware he downloaded from the dark web, on all workstations and servers. Even more worrying and unknown to McGreedy, this malware includes a data-stealing functionality, which the malware author benefits from!

The malware has been executed, and now, a lot of unusual traffic is being generated. What’s more, a large bandwidth of data is seen to be leaving the network.

Forensic McBlue assembles a team to analyse the proxy logs and understand the suspicious network traffic.

Questions

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ubuntu@tryhackme:~/Desktop/artefacts$ cut -d ' ' -f2 access.log | sort | uniq | wc
      9       9     119

How many unique IP addresses are connected to the proxy server?

  • 9
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ubuntu@tryhackme:~/Desktop/artefacts$ cut -d ' ' -f3 access.log | cut -d ':' -f1 | sort | uniq | wc
    111     111    2376

How many unique domains were accessed by all workstations?

  • 111
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ubuntu@tryhackme:~/Desktop/artefacts$ cut -d ' ' -f3 access.log | cut -d ':' -f1 | sort | uniq -c| sort -n | head -n 1
     78 partnerservices.getmicrosoftkey.com
ubuntu@tryhackme:~/Desktop/artefacts$ cut -d ' ' -f3,6 access.log | sort | uniq -c | grep partnerservices.getmicrosoftkey.com
     78 partnerservices.getmicrosoftkey.com:80 503

What status code is generated by the HTTP requests to the least accessed domain?

  • 503
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ubuntu@tryhackme:~/Desktop/artefacts$ cut -d ' ' -f2,3 access.log | sort | uniq -c | sort -nr | head -n 1 | cut -d ':' -f1
   1581 10.10.185.225 frostlings.bigbadstash.thm

Based on the high count of connection attempts, what is the name of the suspicious domain?

  • frostlings.bigbadstash.thm
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ubuntu@tryhackme:~/Desktop/artefacts$ cut -d ' ' -f2,3 access.log | cut -d ':' -f1 | grep frostlings.bigbadstash.thm | uniq   
10.10.185.225 frostlings.bigbadstash.thm

What is the source IP of the workstation that accessed the malicious domain?

  • 10.10.185.225
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ubuntu@tryhackme:~/Desktop/artefacts$ cut -d ' ' -f2,3 access.log | cut -d ':' -f1 | grep frostlings.bigbadstash.thm | wc  
   1581    3162   64821

How many requests were made on the malicious domain in total?

  • 1581
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ubuntu@tryhackme:~/Desktop/artefacts$ grep frostlings.bigbadstash.thm access.log | cut -d '=' -f2 | cut -d ' ' -f1| base64 -d | grep THM
72703959c91cb18edbefedc692c45204,SOC Analyst,THM{a_gift_for_you_awesome_analyst!}

Having retrieved the exfiltrated data, what is the hidden flag?

  • THM{a_gift_for_you_awesome_analyst!}

If you enjoyed doing log analysis, check out the Log Analysis module in the SOC Level 2 Path.

  • No answer needed
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