228 lines
9.0 KiB
Markdown
228 lines
9.0 KiB
Markdown
# Pcap Inspection
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{% hint style="info" %}
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A note about **PCAP** vs **PCAPNG**: there are two versions of the PCAP file format; **PCAPNG is newer and not supported by all tools**. You may need to convert a file from PCAPNG to PCAP using Wireshark or another compatible tool, in order to work with it in some other tools.
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{% endhint %}
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## Online tools for pcaps
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* If the header of your pcap is **broken** you should try to **fix** it using: [http://f00l.de/hacking/**pcapfix.php**](http://f00l.de/hacking/pcapfix.php)
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* Extract **information** and search for **malware** inside a pcap in [**PacketTotal**](https://packettotal.com)
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* Search for **malicious activity** using [**www.virustotal.com**](https://www.virustotal.com) and [**www.hybrid-analysis.com**](https://www.hybrid-analysis.com)
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## Extract Information
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The following tools are useful to extract statistic, files...
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### Wireshark
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{% hint style="info" %}
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**If you are going to analyze a PCAP you basically must to know how to use Wireshark**
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{% endhint %}
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You can find some Wireshark trick in:
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{% content-ref url="wireshark-tricks.md" %}
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[wireshark-tricks.md](wireshark-tricks.md)
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{% endcontent-ref %}
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### Xplico Framework
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[**Xplico** ](https://github.com/xplico/xplico)_(only linux)_ can **analyze** a **pcap** and extract information from it. For example, from a pcap file Xplico extracts each email (POP, IMAP, and SMTP protocols), all HTTP contents, each VoIP call (SIP), FTP, TFTP, and so on.
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#### Install
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```bash
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sudo bash -c 'echo "deb http://repo.xplico.org/ $(lsb_release -s -c) main" /etc/apt/sources.list'
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sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 791C25CE
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sudo apt-get update
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sudo apt-get install xplico
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```
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#### Run
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```
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/etc/init.d/apache2 restart
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/etc/init.d/xplico start
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```
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Access to _**127.0.0.1:9876**_ with credentials _**xplico:xplico**_
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Then create a **new case**, create a **new session** inside the case and **upload the pcap** file.
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### NetworkMiner
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Like Xplico it is a tool to **analyze and extract objects from pcaps**. It has a free edition that you can **download** [**here**](https://www.netresec.com/?page=NetworkMiner). It works with **Windows**.\
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This tool is also useful to get **other information analysed** from the packets in order to be able to know what was happening there in a **quick** way.
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### NetWitness Investigator
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You can download [**NetWitness Investigator from here**](https://www.rsa.com/en-us/contact-us/netwitness-investigator-freeware) **(It works in Windows)**.\
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This is another useful tool that **analyse the packets** and sort the information in a useful way to **know what is happening inside**.
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 (1).png>)
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### [BruteShark](https://github.com/odedshimon/BruteShark)
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* Extracting and encoding usernames and passwords (HTTP, FTP, Telnet, IMAP, SMTP...)
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* Extract authentication hashes and crack them using Hashcat (Kerberos, NTLM, CRAM-MD5, HTTP-Digest...)
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* Build visual network diagram (Network nodes & users)
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* Extract DNS queries
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* Reconstruct all TCP & UDP Sessions
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* File Carving
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### Capinfos
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```
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capinfos capture.pcap
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```
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### Ngrep
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If you are **looking** for **something** inside the pcap you can use **ngrep**. And example using the main filters:
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```bash
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ngrep -I packets.pcap "^GET" "port 80 and tcp and host 192.168 and dst host 192.168 and src host 192.168"
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```
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### Carving
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Using common carving techniques can be useful to extract files and information from the pcap:
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{% content-ref url="../partitions-file-systems-carving/file-data-carving-recovery-tools.md" %}
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[file-data-carving-recovery-tools.md](../partitions-file-systems-carving/file-data-carving-recovery-tools.md)
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{% endcontent-ref %}
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### Capturing credentials
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You can us tools like [https://github.com/lgandx/PCredz](https://github.com/lgandx/PCredz) to parse credentials from a pcap or a live interface.
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## Check Exploits/Malware
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### Suricata
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#### Install and setup
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```
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apt-get install suricata
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apt-get install oinkmaster
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echo "url = http://rules.emergingthreats.net/open/suricata/emerging.rules.tar.gz" >> /etc/oinkmaster.conf
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oinkmaster -C /etc/oinkmaster.conf -o /etc/suricata/rules
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```
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#### Check pcap
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```
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suricata -r packets.pcap -c /etc/suricata/suricata.yaml -k none -v -l log
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```
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### YaraPcap
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[**YaraPCAP**](https://github.com/kevthehermit/YaraPcap) is a tool that
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* Reads a PCAP File and Extracts Http Streams.
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* gzip deflates any compressed streams
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* Scans every file with yara
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* writes a report.txt
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* optionally saves matching files to a Dir
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### Malware Analysis
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Check if you can find any fingerprint of a known malware:
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{% content-ref url="../malware-analysis.md" %}
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[malware-analysis.md](../malware-analysis.md)
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{% endcontent-ref %}
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## Zeek
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> Zeek is a passive, open-source network traffic analyzer. Many operators use Zeek as a network security monitor (NSM) to support investigations of suspicious or malicious activity. Zeek also supports a wide range of traffic analysis tasks beyond the security domain, including performance measurement and troubleshooting.
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Basically, logs created by `zeek` aren't **pcaps**. Therefore you will need to use **other tools** to analyse the logs where the **information** about the pcaps are.
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### Connections Info
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```bash
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#Get info about longest connections (add "grep udp" to see only udp traffic)
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#The longest connection might be of malware (constant reverse shell?)
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cat conn.log | zeek-cut id.orig_h id.orig_p id.resp_h id.resp_p proto service duration | sort -nrk 7 | head -n 10
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10.55.100.100 49778 65.52.108.225 443 tcp - 86222.365445
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10.55.100.107 56099 111.221.29.113 443 tcp - 86220.126151
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10.55.100.110 60168 40.77.229.82 443 tcp - 86160.119664
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#Improve the metrics by summing up the total duration time for connections that have the same destination IP and Port.
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cat conn.log | zeek-cut id.orig_h id.resp_h id.resp_p proto duration | awk 'BEGIN{ FS="\t" } { arr[$1 FS $2 FS $3 FS $4] += $5 } END{ for (key in arr) printf "%s%s%s\n", key, FS, arr[key] }' | sort -nrk 5 | head -n 10
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10.55.100.100 65.52.108.225 443 tcp 86222.4
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10.55.100.107 111.221.29.113 443 tcp 86220.1
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10.55.100.110 40.77.229.82 443 tcp 86160.1
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#Get the number of connectionssummed up per each line
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cat conn.log | zeek-cut id.orig_h id.resp_h duration | awk 'BEGIN{ FS="\t" } { arr[$1 FS $2] += $3; count[$1 FS $2] += 1 } END{ for (key in arr) printf "%s%s%s%s%s\n", key, FS, count[key], FS, arr[key] }' | sort -nrk 4 | head -n 10
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10.55.100.100 65.52.108.225 1 86222.4
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10.55.100.107 111.221.29.113 1 86220.1
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10.55.100.110 40.77.229.82 134 86160.1
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#Check if any IP is connecting to 1.1.1.1
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cat conn.log | zeek-cut id.orig_h id.resp_h id.resp_p proto service | grep '1.1.1.1' | sort | uniq -c
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#Get number of connections per source IP, dest IP and dest Port
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cat conn.log | zeek-cut id.orig_h id.resp_h id.resp_p proto | awk 'BEGIN{ FS="\t" } { arr[$1 FS $2 FS $3 FS $4] += 1 } END{ for (key in arr) printf "%s%s%s\n", key, FS, arr[key] }' | sort -nrk 5 | head -n 10
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### RITA
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#Something similar can be done with the tool rita
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rita show-long-connections -H --limit 10 zeek_logs
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+---------------+----------------+--------------------------+----------------+
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| SOURCE IP | DESTINATION IP | DSTPORT:PROTOCOL:SERVICE | DURATION |
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+---------------+----------------+--------------------------+----------------+
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| 10.55.100.100 | 65.52.108.225 | 443:tcp:- | 23h57m2.3655s |
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| 10.55.100.107 | 111.221.29.113 | 443:tcp:- | 23h57m0.1262s |
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| 10.55.100.110 | 40.77.229.82 | 443:tcp:- | 23h56m0.1197s |
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#Get connections info from rita
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rita show-beacons zeek_logs | head -n 10
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Score,Source IP,Destination IP,Connections,Avg Bytes,Intvl Range,Size Range,Top Intvl,Top Size,Top Intvl Count,Top Size Count,Intvl Skew,Size Skew,Intvl Dispersion,Size Dispersion
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1,192.168.88.2,165.227.88.15,108858,197,860,182,1,89,53341,108319,0,0,0,0
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1,10.55.100.111,165.227.216.194,20054,92,29,52,1,52,7774,20053,0,0,0,0
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0.838,10.55.200.10,205.251.194.64,210,69,29398,4,300,70,109,205,0,0,0,0
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```
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### DNS info
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```bash
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#Get info about each DNS request performed
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cat dns.log | zeek-cut -c id.orig_h query qtype_name answers
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#Get number of times each domain was requestedand get top 10
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cat dns.log | zeek-cut query | sort | uniq | rev | cut -d '.' -f 1-2 | rev | sort | uniq -c | sort -nr | head -n 10
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#Get all the IPs
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cat dns.log | zeek-cut id.orig_h query | grep 'example\.com' | cut -f 1 | sort | uniq -c
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#Sort the most common dnsrecord request (should be A)
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cat dns.log | zeek-cut qtype_name | sort | uniq -c | sort -nr
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#See top DNS domain requested with rita
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rita show-exploded-dns -H --limit 10 zeek_logs
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```
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## Other pcap analysis tricks
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{% content-ref url="dnscat-exfiltration.md" %}
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[dnscat-exfiltration.md](dnscat-exfiltration.md)
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{% endcontent-ref %}
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{% content-ref url="wifi-pcap-analysis.md" %}
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[wifi-pcap-analysis.md](wifi-pcap-analysis.md)
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{% endcontent-ref %}
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{% content-ref url="usb-keystrokes.md" %}
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[usb-keystrokes.md](usb-keystrokes.md)
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{% endcontent-ref %}
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