on the World Anti-Doping Agency ( WADA ) , also allegedly perpetratedAttack.Databreachby Kremlin-backed hackers , data on Therapeutic Use Exemption ( TUE ) applications were targeted . TUEs allow athletes to take normally-prohibited substances where they 're required , such as when they suffer from an illness . Sebastian Coe , an Olympic champion and current IAAF president , said the organization apologized to athletes affected by the hack , which dated back to at least February 21 . It was only this weekend , however , that the IAAF and partner organizations carried out a `` complex remediation across all systems and servers in order to remove the attackers ' access to the network , '' according to the official statement . On first inspection , it appeared data on TUEs was collectedAttack.Databreachfrom a file server and stored in a newly created file , though it was n't clear if the information had been takenAttack.Databreachoutside the network . `` Our first priority is to the athletes who have provided the IAAF with information that they believed would be secure and confidential , '' said Coe . The IAAF 's contractor , Context Information Security , discovered the breach . The find came after the security firm was asked by the IAAF in January to `` conduct a proactive and thorough technical investigation across its systems , which led to the discovery of a sophisticated intrusion , '' a Context spokesperson told Forbes via email . The company was confident Fancy Bear , also known as APT28 , was responsible . `` The threat intelligence team at Context Information Security has tracked the tools , techniques and procedures of Fancy Bear/APT28 for a number of years , through our own investigations and through collaboration with many other cyber security researchers [ and ] organizations . Our findings in this investigation give us a high degree of confidence that this cyber attack can be attributed to Fancy Bear/APT28 . '' In response to a question about the time it took from discovery in February to throwing the hackers off the network at the start of April , the spokesperson said the parties needed to collect forensic images to `` better understand how the attacks were carried out , what information may have been compromisedAttack.Databreach. '' `` By taking the time to fully investigate the attack , the IAAF was able to remove the attackers ' access to the network as effectively as possible , '' the spokesperson added . If IAAF had gone public with this before the investigation was complete and before the attackers ' access was removed , the attackers may have been tipped off to the investigation and performed further malicious actions . The Facebook page for the WADA hackers , who posted under the pluralized name Fancy Bears , has not been updated since December 2016 . Though the TUEs show athletes legally use normally-banned substances , the Fancy Bear hacks still caused trouble for some athletes . Those affected by last year 's attacks on WADA and the USADA hit huge names across a range of sports , including tennis giants Serena and Venus Williams , and Rafael Nadal , as well as cycling superstar Bradley Wiggins , who continues to contest rumors about Team Sky 's operations . The Fancy Bear group was accused by multiple security companies , the DHS and the FBI of being sponsored by the Russian government and of carrying out the significant breach of the Democratic National Committee ( DNC ) .