How to easily decrypt an Md5 password

Md5 ciphertext cracking (decryption) is an indispensable part of network attacks and an important "auxiliary tool" in hacking tools ". Md5 decryption is mainly used for network attacks. During the website intrusion process, attackers may obtain the account and password values (md5 encrypted values) of administrators or other users ). There are two possible password values: plaintext and plaintext. If the password value is encrypted, You need to determine the password value. If md5 encryption is used, you can use software such as MD5Crack3 to crack the password. Professor Wang Xiaoyun's md5 password collision cracking algorithm has not been published. Therefore, currently, Md5 decryption methods mainly adopt brute-force cracking. That is, the software uses algorithms to generate a dictionary and then uses the md5 function to encrypt the values in the dictionary to form a ciphertext, then compare it with the ciphertext to be cracked. If it is the same, the attack is considered successful. Currently, many websites on the Internet provide md5 encryption or encryption value queries, and input the encrypted md5 value to the website. If the md5 value exists in the website database, the md5 value corresponding to this value is the password before encryption. This case describes how to use MD5Crack3 and some online websites to crack; MD5Crack3 is a md5 password cracking software written by a stay, its website address: Login (http://simeon.blog.51cto.com/18680/144558) to download.

(1) generate an md5 password value online

1. md5 encryption and decryption knowledge

Md5 ciphertext cracking (decryption) is an indispensable part of network attacks and an important "auxiliary tool" in hacking tools ". Md5 decryption is mainly used for network attacks. During the website intrusion process, attackers may obtain the account and password values (md5 encrypted values) of administrators or other users ). There are two possible password values: plaintext and plaintext. If the password value is encrypted, You need to determine the password value. If md5 encryption is used, you can use software such as MD5Crack4 to crack the password. Professor Wang Xiaoyun's md5 password collision cracking algorithm has not been published. Therefore, currently, Md5 decryption methods mainly adopt brute-force cracking. That is, the software uses algorithms to generate a dictionary and then uses the md5 function to encrypt the values in the dictionary to form a ciphertext, then compare it with the ciphertext to be cracked. If it is the same, the attack is considered successful. Currently, many websites on the Internet provide md5 encryption or encryption value queries, and input the encrypted md5 value to the website. If the md5 value exists in the website database, the md5 value corresponding to this value is the password before encryption.

2. generate an md5 password through website iis5

Enter the address "login" in the browser:

MD5 (goodman88, 32) = d5a8e0b115259023faa219f5b53ca522

MD5 (goodman88, 16) = 15259023faa219f5

　　

Figure 1 md5 Encryption

As experiment data, we generate a set of md5 passwords for birthdays as follows:

MD5 (19801230,32) = 2540bb62336a8eb3ebc1e42ee44c8e3d

MD5 (19801230,16) = 336a8eb3ebc1e42e

(2) Online md5 password cracking

1. Crack the md5 password through website iis5

Enter the encrypted md5 32 value "d5a8e0b115259023faa219f5b53ca522" in the input box of iis5 website, and click "md5 encryption or decryption". As shown in figure 2, the attack fails.

　　

Figure 2 failed to crack the md5 password through website iis5

Add the md5 value "2540bb62336a8eb3ebc1e42ee44c8e3d" after the second birthday encryption to the website "iis5 for cracking. Soon the result is displayed, as shown in figure 3.

　　

Figure 3 cracking a simple digital password

2. Online md5 cracking the website charges for cracking the difficult md5 password value

Some online websites provide md5 password cracking, which can only be included and some simple passwords. For a slightly more complex password, it is not easy to crack; in addition, for some md5 password values that are a little difficult, if there is a database, online websites require payment, for example, using a complicated md5 value for cracking, as shown in 4, the prompt is found, however, payment is required.

　　

Figure 4 pay-as-you-go is required to view the md5 password value

(3) use the dictionary to brute force crack the md5 password value

1. Generate the md5 password value again

Then, generate the md5 password with the original password "jimmychu246" on website 5 as follows:

MD5 (jimmychu246, 32) = 437f4fffb6b2e5aaca9fd1712b8ad282

MD5 (jimmychu246, 16) = b6b2e5aaca9fd171

Run md5crack4 directly, as shown in Figure 5.

　　

Figure 5 main interface of the md5crack4 Program

2. Verify the md5 value in md5crack4

Paste the md5 value (437f4fffb6b2e5aaca9fd1712b8ad282) to the "Single Cryptograph" input box, as shown in figure 6. If the md5 value is correct, the black "valid (valid)" character is displayed under the "cracking a single ciphertext" input box; otherwise, the "valid" is displayed as gray.

　　

3. dictionary cracking

In Plaintext Setting, select Dictionary and select three different dictionaries in N0.1, N0.2, and N0.3, after the selection is complete, click the "Start" button to Start md5 cracking. After the cracking is complete, a corresponding prompt is displayed, as shown in 7. dictionary cracking is successfully used in this case, the "jimmychu246" password is displayed in the Result ".

　　

Figure 7 dictionary cracking
4. Use numbers in the character set (Char Muster) to crack

Put the md5 value "336a8eb3ebc1e42e" in the single md5 password cracking input box, and select "Char Muster, in this example, you can select "Number", "lowercase", "majuscule", "special char", and "custom" for cracking, and use numbers for cracking, therefore, set "1" in "Min Length", "Max Length" to "8", and click "start, use numbers for md5 cracking. The number of attempts to crack the password ranges from 1 ~ The password value is successfully cracked, as shown in 8. The result is "336a8eb3ebc1e42e ---> [9999999]".

　　

Figure 8 cracking with numbers

& Description

(1) In md5crack4, you can also define combinations of numbers, letters, and special characters for cracking.

(2) If the computer configuration is better, you can set more threads.

(3) For custom cracking, we recommend that you first select a number, followed by a combination of numbers, letters, and special characters. It is easy to crack, or it takes too long to crack.

(4) In md5crack4, you can also use the plug-in to crack it.

(5) In md5crack4, you can also set the language version displayed for the software. There are two versions, simplified Chinese and English. Click Option on the main interface to set the language version, as shown in figure 9.

　　

Figure 9 set md5crack4

5. Crack multiple passwords at a time

Store all the md5 passwords to be cracked in a txt file. Each password is an independent line. Then, click "crack multiple ciphertext" in md5crack4 and select the md5 password file you just edited, 10. Select a method to crack the attack. In this case, select a digital dictionary to crack the attack, and click "start.

　　

Figure 10 cracking multiple md5 passwords

The cracking result is displayed in the lower-right corner of md5crack4. Click "log" to view md5 value verification and other log information. Click "result" to view the cracking result, as shown in Figure 11, in the result, the md5 value corresponds to the original password one by one.

　　

Figure 11 cracking results

Md5 encryption and decryption is a must-have knowledge in Network Attack and Defense. This article describes how to use md5cracker to crack the md5 value through websites, you can first crack some md5 websites. If the website fails to crack, you can use md5cracker locally to crack the website.