Terrorism, extremism, and killing innocent people is clearly prohibited in Islam. Allah clearly states in the Quran, “Allah does not forbid you from dealing kindly and fairly with those who have neither fought nor driven you out of your homes. Surely Allah loves those who are fair. Allah only forbids you from befriending those who have fought you for ˹your˺ faith, driven you out of your homes, or supported ˹others˺ in doing so. And whoever takes them as friends, then it is they who are the ˹true˺ wrongdoers” (Quran 60:8-9). These verses show that Muslims are prohibited to treat the non-Muslims who don’t try to harm them in a bad or unjust manner, let alone killing them. In another verse, Allah states, “That is why We ordained for the Children of Israel that whoever takes a life—unless as a punishment for murder or mischief in the land—it will be as if they killed all of humanity; and whoever saves a life, it will be as if they saved all of humanity” (Quran 5:32). This verse shows the value Allah has put on just one innocent soul. So in short, no, ISIS doesn’t come from Islamic teachings, as there are extremist groups in every religion.
And Allah knows best.