किं वा दुर्जनसङ्गतिर्नकुरुते लोकद्वयद्वंसिनी

पापं वर्धयते चिनोति कुमतिं कीर्त्यङ्गना नश्यति

धर्मं ध्वंसयते तनोति विपदं सम्पत्तिमुन्मर्दति।

नीतिं हन्ति विनीतिमत्र कुरुते कोपं धुनीते शमं किं

वा दुर्जनसङ्गतिर्नकुरुते लोकद्वयद्वंसिनी॥

subhashita ratna sandoha 

pāpaṁ vardhayate cinoti kumatiṁ kīrtyaṅganā naśyati

dharmaṁ dhvaṁsayate tanoti vipadaṁ sampattimunmardati|

nītiṁ hanti vinītimatra kurute kopaṁ dhunīte śamaṁ kiṁ

vā durjanasaṅgatirnakurute lokadvayadvaṁsinī||

Association with evil-minded people would lead to

Increase in the accumulation of sins

It, ensures that the accumulation of bad tendencies in mind are multiplied

Your name and fame which has been as attractive as a beautiful damsel just gets disfigured

Your sense of propriety and desire to tread the path of Dharma are shattered

It invites unwanted dangers and risks

Destroys whatever accumulation of wealth and fortune you have

Effectively kills justice and actively helps to ensure the rule of injustice and unfairness

Flares up your anger and other base and violent propensities and destroys calmness and peace of mind

Yes, what damage can be there which is beyond the evil grip of bad company..

It destroys your welfare in both the worlds.. In the world you live when you are alive and in the world you have to go after you die too.