The Talmud (Brachot 28b, 29a) says that due to problems caused by the Minim, the sages decided to ask Shmuel Hakatan to compose a special new blessing to be inserted into the Amida (Shmoneh Esrei prayer) against the Minim.
But in the current Ashkenazic version of the prayer, no explicit mention of the Minim is mentioned. Why?
The answer is that we Ashkenazim have a censored version of the prayer.
In Siddur Vilna, the following is claimed to be the pre-censorship version of the prayer.
ולמשמדים אל תהי תקוה, וכל המינים כרגע יאבדו, וכל איביׁ(אויבי) עמך מהרה יכרתו ומלכות זדון מהרה תעקר ותשבר ותמגר, ותכניע במהרה בימינו. ברוך אתה ה' שובר איבים (אויבים) ומכניע זדים
It should be added that other Jewish communities [that do not use the Ashkenazic version of the prayer book] do have some mention of Minim in their version of the blessing but not exactly like the one quoted above. Also there is a slight variation of the wording between different communities that mention the Minim in their prayers.