9 KiB
Pcap Inspection
{% hint style="info" %} 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. {% endhint %}
Online tools for pcaps
- If the header of your pcap is broken you should try to fix it using: http://f00l.de/hacking/pcapfix.php****
- Extract information and search for malware inside a pcap in PacketTotal****
- Search for malicious activity using www.virustotal.com and www.hybrid-analysis.com****
Extract Information
The following tools are useful to extract statistic, files...
Wireshark
{% hint style="info" %} If you are going to analyze a PCAP you basically must to know how to use Wireshark {% endhint %}
You can find some Wireshark trick in:
{% content-ref url="wireshark-tricks.md" %} wireshark-tricks.md {% endcontent-ref %}
Xplico Framework
****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.
Install
sudo bash -c 'echo "deb http://repo.xplico.org/ $(lsb_release -s -c) main" /etc/apt/sources.list'
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 791C25CE
sudo apt-get update
sudo apt-get install xplico
Run
/etc/init.d/apache2 restart
/etc/init.d/xplico start
Access to _**127.0.0.1:9876 **_with credentials xplico:xplico
Then create a new case, create a new session inside the case and upload the pcap file.
NetworkMiner
Like Xplico it is a tool to analyze and extract objects from pcaps. It has a free edition that you can **download **here. It works with Windows.
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.
NetWitness Investigator
You can download NetWitness Investigator from here** (It works in Windows)**.
This is another useful tool that analyse the packets and sort the information in a useful way to know what is happening inside.
BruteShark
- Extracting and encoding usernames and passwords (HTTP, FTP, Telnet, IMAP, SMTP...)
- Extract authentication hashes and crack them using Hashcat (Kerberos, NTLM, CRAM-MD5, HTTP-Digest...)
- Build visual network diagram (Network nodes & users)
- Extract DNS queries
- Reconstruct all TCP & UDP Sessions
- File Carving
Capinfos
capinfos capture.pcap
Ngrep
If you are looking for something inside the pcap you can use ngrep. And example using the main filters:
ngrep -I packets.pcap "^GET" "port 80 and tcp and host 192.168 and dst host 192.168 and src host 192.168"
Carving
Using common carving techniques can be useful to extract files and information from the pcap:
{% content-ref url="../partitions-file-systems-carving/file-data-carving-recovery-tools.md" %} file-data-carving-recovery-tools.md {% endcontent-ref %}
Capturing credentials
You can us tools like https://github.com/lgandx/PCredz to parse credentials from a pcap or a live interface.
Check Exploits/Malware
Suricata
Install and setup
apt-get install suricata
apt-get install oinkmaster
echo "url = http://rules.emergingthreats.net/open/suricata/emerging.rules.tar.gz" >> /etc/oinkmaster.conf
oinkmaster -C /etc/oinkmaster.conf -o /etc/suricata/rules
Check pcap
suricata -r packets.pcap -c /etc/suricata/suricata.yaml -k none -v -l log
YaraPcap
****YaraPCAP is a tool that
- Reads a PCAP File and Extracts Http Streams.
- gzip deflates any compressed streams
- Scans every file with yara
- writes a report.txt
- optionally saves matching files to a Dir
Malware Analysis
Check if you can find any fingerprint of a known malware:
{% content-ref url="../malware-analysis.md" %} malware-analysis.md {% endcontent-ref %}
Zeek
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.
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.
Connections Info
#Get info about longest connections (add "grep udp" to see only udp traffic)
#The longest connection might be of malware (constant reverse shell?)
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
10.55.100.100 49778 65.52.108.225 443 tcp - 86222.365445
10.55.100.107 56099 111.221.29.113 443 tcp - 86220.126151
10.55.100.110 60168 40.77.229.82 443 tcp - 86160.119664
#Improve the metrics by summing up the total duration time for connections that have the same destination IP and Port.
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
10.55.100.100 65.52.108.225 443 tcp 86222.4
10.55.100.107 111.221.29.113 443 tcp 86220.1
10.55.100.110 40.77.229.82 443 tcp 86160.1
#Get the number of connectionssummed up per each line
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
10.55.100.100 65.52.108.225 1 86222.4
10.55.100.107 111.221.29.113 1 86220.1
10.55.100.110 40.77.229.82 134 86160.1
#Check if any IP is connecting to 1.1.1.1
cat conn.log | zeek-cut id.orig_h id.resp_h id.resp_p proto service | grep '1.1.1.1' | sort | uniq -c
#Get number of connections per source IP, dest IP and dest Port
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
### RITA
#Something similar can be done with the tool rita
rita show-long-connections -H --limit 10 zeek_logs
+---------------+----------------+--------------------------+----------------+
| SOURCE IP | DESTINATION IP | DSTPORT:PROTOCOL:SERVICE | DURATION |
+---------------+----------------+--------------------------+----------------+
| 10.55.100.100 | 65.52.108.225 | 443:tcp:- | 23h57m2.3655s |
| 10.55.100.107 | 111.221.29.113 | 443:tcp:- | 23h57m0.1262s |
| 10.55.100.110 | 40.77.229.82 | 443:tcp:- | 23h56m0.1197s |
#Get connections info from rita
rita show-beacons zeek_logs | head -n 10
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
1,192.168.88.2,165.227.88.15,108858,197,860,182,1,89,53341,108319,0,0,0,0
1,10.55.100.111,165.227.216.194,20054,92,29,52,1,52,7774,20053,0,0,0,0
0.838,10.55.200.10,205.251.194.64,210,69,29398,4,300,70,109,205,0,0,0,0
DNS info
#Get info about each DNS request performed
cat dns.log | zeek-cut -c id.orig_h query qtype_name answers
#Get number of times each domain was requestedand get top 10
cat dns.log | zeek-cut query | sort | uniq | rev | cut -d '.' -f 1-2 | rev | sort | uniq -c | sort -nr | head -n 10
#Get all the IPs
cat dns.log | zeek-cut id.orig_h query | grep 'example\.com' | cut -f 1 | sort | uniq -c
#Sort the most common dnsrecord request (should be A)
cat dns.log | zeek-cut qtype_name | sort | uniq -c | sort -nr
#See top DNS domain requested with rita
rita show-exploded-dns -H --limit 10 zeek_logs
Other pcap analysis tricks
{% content-ref url="dnscat-exfiltration.md" %} dnscat-exfiltration.md {% endcontent-ref %}
{% content-ref url="wifi-pcap-analysis.md" %} wifi-pcap-analysis.md {% endcontent-ref %}
{% content-ref url="usb-keystrokes.md" %} usb-keystrokes.md {% endcontent-ref %}