श्रीमत्परमहंसस्वामिब्नह्यानन्द विरचितं
At the beginning it states that the Sri Haristotram was composed by Paramahamsaswaami Brahmaananda.
There is not much information available online as to which Brahmananda Swami it is referring too. There have been many people with similar names such as Swami Brahmananda of the Swami Narayana Sect, the former Shankarcharya of Jyotir Math who is called Swami Brahmananda, and Swami Brahmananda the shishya of Ramakrishna, and etc.
Regardless though, he has composed a number of works listed and avaliable on this site: https://stotram.co.in/authors/paramahamsa-brahmananda/. These works are:
Abhilasha Ashtakam 3, Deenabandhu Ashtakam, Gopala Ashtakam, Govinda Ashtakam (By Paramahamsa Brahmananda), Hari Nama Ashtakam, Hari Sharanashtakam, Hari Stotram, Kamalapatya Ashtakam, Krishana Ashtakam 6 (By Paramahamsa Brahmananda), Rama Ashtakam (By Paramahamsa Brahmananda), Ramapatya Ashtakam, Shankarashtakam, Vishnu Mahimna Stotram.

Sri Haristotram in Devanagari: https://prapatti.com/slokas/sanskrit/haristotram.pdf
Sri Haristotram in Roman: https://prapatti.com/slokas/english/haristotram.pdf