In a ping response TTL: 127 = Windows 254 = Cisco Lo demás,algunlinux

$1$- md5 $2$or $2a$ - Blowfish $5$- sha256 $6$- sha512

If you do not know what is behind a service, try to make and HTTP GET request.

UDP Scans nc -nv -u -z -w 1 <IP> 160-16

An empty UDP packet is sent to a specific port. If the UDP port is open, no reply is sent back from the target machine. If the UDP port is closed, an ICMP port unreachable packet should be sent back from the target machine.

UDP port scanning is often unreliable, as firewalls and routers may drop ICMP packets. This can lead to false positives in your scan, and you will regularly see UDP port scans showing all UDP ports open on a scanned machine. o Most port scanners do not scan all available ports, and usually have a preset list of “interesting ports” that are scanned.

CTF - Tricks

In Windows use Winzip to search for files. Alternate data Streams: dir /r | find ":$DATA"

binwalk --dd=".*" <file> #Extract everything
binwalk -M -e -d=10000 suspicious.pdf #Extract, look inside extracted files and continue extracing (depth of 10000)

Crypto

featherduster

Basae64(6—>8) —> 0...9, a...z, A…Z,+,/ Base32(5 —>8) —> A…Z, 2…7 Base85 (Ascii85, 7—>8) —> 0...9, a...z, A...Z, ., -, :, +, =, ^, !, /, *, ?, &, <, >, (, ), [, ], {, }, @, %, $, # Uuencode --> Start with "begin <mode> <filename>" and weird chars Xxencoding --> Start with "begin <mode> <filename>" and B64 Vigenere (frequency analysis) —> https://www.guballa.de/vigenere-solver Scytale (offset of characters) —> https://www.dcode.fr/scytale-cipher​

25x25 = QR

factordb.com rsatool

Snow --> Hide messages using spaces and tabs

Characters

%E2%80%AE => RTL Character (writes payloads backwards)