28 lines
925 B
Markdown
28 lines
925 B
Markdown
# DNSCat pcap analysis
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If you have pcap with data being **exfiltrated by DNSCat** (without using encryption), you can find the exfiltrated content.
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You only need to know that the **first 9 bytes** are not real data but are related to the** C\&C communication**:
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```python
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from scapy.all import rdpcap, DNSQR, DNSRR
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import struct
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f = ""
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last = ""
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for p in rdpcap('ch21.pcap'):
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if p.haslayer(DNSQR) and not p.haslayer(DNSRR):
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qry = p[DNSQR].qname.replace(".jz-n-bs.local.","").strip().split(".")
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qry = ''.join(_.decode('hex') for _ in qry)[9:]
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if last != qry:
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print(qry)
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f += qry
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last = qry
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#print(f)
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```
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For more information: [https://github.com/jrmdev/ctf-writeups/tree/master/bsidessf-2017/dnscap](https://github.com/jrmdev/ctf-writeups/tree/master/bsidessf-2017/dnscap)\
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[https://github.com/iagox86/dnscat2/blob/master/doc/protocol.md](https://github.com/iagox86/dnscat2/blob/master/doc/protocol.md)
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