A great achievement of Islam is that Islam rejects conjectures without any evidence and gave the neat and clean belief of Tawheed (oneness of Allah) in which there is no room for blind belief and superstition.

Islam`s Holy Book, the Qur’an, strongly opposes all superstitious beliefs.

There are many verses of the Quraan which clearly explains this.
عَـٰلِمُ ٱلْغَيْبِ فَلَا يُظْهِرُ عَلَىٰ غَيْبِهِۦٓ أَحَدًا
He Alone knows the unseen. He does not reveal His secrets to anyone [Al Jinn 72: 26]

There are also various Hadith in which the Prophet ﷺ had clearly and definitively rejected and refuted superstitions in all its various forms.
عَنْ جَابِرٍ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم‏ لاَ عَدْوَى وَلاَ طِيَرَةَ وَلاَ غُولَ ‏
Jabir RA reported Allah’s Messenger (ﷺ) as saying: There is no transitive disease, no ill omen, no ghoul (no evil-spirit or ghost). [Sahih Muslim 2222a]

The majority of scholars interpret this to mean that these things in and of themselves do not transmit or cause harm through supernatural or hidden means but that Allah is ultimately in control and any fearful superstition around these is false.
لا عدوى ولا طيرة ولا هامة ولا صفر
There is no contagiousness in diseases, no bad omens, no bad luck in an owl and no bad luck in the month of Safar [Bukhari and Muslim]

عَنْ أَبِي، هُرَيْرَةَ حِينَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏”‏ لاَ عَدْوَى وَلاَ صَفَرَ وَلاَ هَامَةَ ‏”‏ ‏.‏ فَقَالَ أَعْرَابِيٌّ يَا رَسُولَ اللَّهِ فَمَا بَالُ الإِبِلِ تَكُونُ فِي الرَّمْلِ كَأَنَّهَا الظِّبَاءُ فَيَجِيءُ الْبَعِيرُ الأَجْرَبُ فَيَدْخُلُ فِيهَا فَيُجْرِبُهَا كُلَّهَا قَالَ ‏”‏ فَمَنْ أَعْدَى الأَوَّلَ
Abu Huraira RA reported Allah’s Messenger ﷺ as saying: There is no infection, no safar, no hama. A desert Arab said: Allah’s Messenger, how is it that when the camel is in the sand it is like a deer-then a camel afflicted with scab mixes with it and it is affected by it? He (the Holy Prophet) ﷺ said: Who infected the first one? [Sahih Muslim 2220a]

Previously people regarded this month as an unlucky month.
Rasulullah ﷺ established the Deen of Islam and put an end to such incorrect beliefs. Unfortunately, these beliefs still lingers along with many people today.

It is against the grain of Imaan to believe in superstition which is tantamount to Shirk. There are various forms of Shirk (associating partners with Allah.) If a person believes that anything besides Allah has the power to do things, then it is equal to believing that, such a thing is equal to Allah in power. For example, some people believe that if a cat crosses the road whilst one is driving, it indicates that an accident will occur. This is regarded as superstition. Allah alone has the power of all things. All good and bad comes to us from Allah and a cat has nothing to do with it.