# Wireshark

## Information about Pcap Files

Get information about a given PCAP file in the following way.

```sh
capinfos example.pcap
```

Show verbose package information and bytes inside the package.

```sh
tshark -r example.pcapng -V -x
```

Autostop `-a` and ringbuffer `-b` arguments may  be set to stop or split files
at defined duration `duration:10`, sizes `filesize:100`, and count of files
`files:5`.

## Extracting USB Keystrokes

Data between USB devices and the host can be filtered via tshark in order to
display just the payload, e.g. keystrokes in the following way

```sh
tshark -r keystrokes.pcapng -Y "usb.transfer_type==0x01 and frame.len==35 and! (usb.capdata == 00:00:00:00:00:00:00:00)" -T fields -e usbhid.data > output.txt
```

A lookup table is needed to [convert the USBHID data to ASCII values](https://gist.github.com/ImAnEnabler/091a9e1ee2d6a0805408e009e2f4a2b5) 

```sh
python keystrokedecoder.py output.txt
```

## Extracting Payload sent in DNS Request

Search for the DNS requests containing the specific top level domain.

```sh
tshark -r capture.pcapng  -Y 'dns && ip.dst==167.71.211.113 && (dns contains xyz)' -T fields -e dns.qry.name | awk -F '.' '{print $1}' | uniq > dns.out
```

## NTLMv2 hash Reconstruction via SMBv2

Session setup of SMBv2 leaves enough information to reconstruct the NTLMv2 hash.
Take a look at the second and third packets of the initialization, namely
`Session Setup Response, Error: STATUS_MORE_PROCESSING_REQUIRED, NTLMSSP_CHALLENGE`
and `Session Setup Request, NTLMSSP_AUTH, User: <DOMAIN\USERNAME>`.

The scheme of an NTLMv2 hash is the following.

```
[User name]::[Domain name]:[NTLM Server Challenge]:[NTProofStr]:[Rest of NTLMv2 Response]
```

The `NTLM Server Challenge` can be found inside the `Security Blob` of the
request from the server.
`User name`, `Domain name` and `NTLMv2 Response` can be found inside the
`Security Blob` inside the response sent by the client. `NTProofStr` is the
first part of the `NTLM Response`. Set a `:` between `NTProofStr` and the rest
of the `NTLMv2 Response`.