Experts at Google and CWI conducted the first real world collision attack against popular SHA-1 hashing algorithm, so called shattered-attack. A successful collision attack could be exploited by hackers to forge digital signatures. The attack is 100,000 times faster than a brute-force attack, it required nine quintillion (9,223,372,036,854,775,808) computations. The cost of computing the second block of the attack by renting Amazon instances can be estimated from these various data, it would cost roughly $560,000 for the necessary 71 device years.”]
Source: https://securityaffairs.co/wordpress/56608/hacking/shattered-attack.html