How to Bruteforce Gmail Password Using the Termux Application on Android

Passwords are the most commonly used method for user authentication. Passwords are so popular because the logic behind them makes sense to people and they’re relatively easy for developers to implement. However, passwords can also introduce security vulnerabilities. Password crackers are designed to take credential data stolen in a data breach or other hack and extract passwords from it.

What is password cracking?

A well-designed password-based authentication system doesn’t store a user’s actual password. This would make it far too easy for a hacker or a malicious insider to gain access to all of the user accounts on the system. Instead, authentication systems store a password hash, which is the result of sending the password — and a random value called a salt — through a hash function. Hash functions are designed to be one-way, meaning that it is very difficult to determine the input that produces a given output. Since hash functions are also deterministic (meaning that the same input produces the same output), comparing two password hashes (the stored one and the hash of the password provided by a user) is almost as good as comparing the real passwords.

Password cracking refers to the process of extracting passwords from the associated password hash. This can be accomplished in a few different ways:

Dictionary attack:

Most people use weak and common passwords. Taking a list of words and adding a few permutations — like substituting $ for s — enables a password cracker to learn a lot of passwords very quickly.

Brute-force guessing attack:

There are only so many potential passwords of a given length. While slow, a brute-force attack (trying all possible password combinations) guarantees that an attacker will crack the password eventually.

Hybrid attack:

A hybrid attack mixes these two techniques. It starts by checking to see if a password can be cracked using a dictionary attack, then moves on to a brute-force attack if it is unsuccessful. Most password-cracking or password finder tools enable a hacker to perform any of these types of attacks. This post describes some of the most commonly used password-cracking tools.

1. Hashcat

Hashcat is one of the most popular and widely used password crackers in existence. It is available on every operating system and supports over 300 different types of hashes. Hashcat enables highly parallelized password cracking with the ability to crack multiple different passwords on multiple different devices at the same time and the ability to support a distributed hash-cracking system via overlays. Cracking is optimized with integrated performance tuning and temperature monitoring.

Download Hashcat here.

2. John the Ripper

John the Ripper is a well-known free open-source password cracking tool for Linux, Unix and Mac OS X. A Windows version is also available. John the Ripper offers password cracking for a variety of different password types. It goes beyond OS passwords to include common web apps (like WordPress), compressed archives, document files (Microsoft Office files, PDFs and so on), and more. A pro version of the tool is also available, which offers better features and native packages for target operating systems. You can also download Openwall GNU/*/Linux that comes with John the Ripper.

Download John the Ripper here.

3. THC Hydra

THC Hydra is an online password-cracking tool that attempts to determine user credentials via brute-force password guessing attack. It is available for Windows, Linux, Free BSD, Solaris and OS X. THC Hydra is extensible with the ability to easily install new modules. It also supports a number of network protocols, including Asterisk, AFP, Cisco AAA, Cisco auth, Cisco enable, CVS, Firebird, FTP, HTTP-FORM-GET, HTTP-FORM-POST, HTTP-GET, HTTP-HEAD, HTTP-PROXY, HTTPS-FORM-GET, HTTPS-FORM-POST, HTTPS-GET, HTTPS-HEAD, HTTP-Proxy, ICQ, IMAP, IRC, LDAP, MS-SQL, MYSQL, NCP, NNTP, Oracle Listener, Oracle SID, Oracle, PC-Anywhere, PCNFS, POP3, POSTGRES, RDP, Rexec, Rlogin, Rsh, SAP/R3, SIP, SMB, SMTP, SMTP Enum, SNMP, SOCKS5, SSH (v1 and v2), Subversion, Teamspeak (TS2), Telnet, VMware-Auth, VNC, and XMPP.

Download THC Hydra here.

4. Aircrack-ng

Aircrack-ng is a Wi-Fi password-cracking tool that can crack WEP or WPA/WPA2 PSK passwords. It analyzes wireless encrypted packets and then tries to crack passwords via the dictionary attacks and the PTW, FMS, and other cracking algorithms. It is available for Linux and Windows systems. A live CD of Aircrack is also available.

Download Aircrack-ng here.

5. RainbowCrack

All password-cracking is subject to a time-memory tradeoff. If an attacker has precomputed a table of password/hash pairs and stored them as a “rainbow table,” then the password-cracking process is simplified to a table lookup. This threat is why passwords are now salted: adding a unique, random value to every password before hashing means that the number of rainbow tables required is much larger. RainbowCrack is a password-cracking tool designed to work using rainbow tables. It is possible to generate custom rainbow tables or take advantage of preexisting ones downloaded from the internet. RainbowCrack offers free downloads of rainbow tables for the LANMAN, NTLM, MD5, and SHA1 password systems.

Download rainbow tables here.