Is it permissible to change one's surname to a word meaning "immigrant" in the language of a foreign country to avoid social and material problems, knowing that some original inhabitants of that country bear this surname?

It is forbidden to attribute oneself to a tribe or family other than one's own, due to the Prophet's (peace be upon him) saying: "(There is) no man who claims to be the son of other than his father, while he knows him (to be his father), except that he has disbelieved. And whoever claims kinship with a people in whom he has no lineage, let him take his seat in the Fire." This applies if one attributes oneself to a known people or family. However, if one attributes oneself to an unknown name or title, such as "al-Muhajir" (the Migrant) or "al-Ghareeb" (the Stranger), there is no harm in that. This was common during the time of the Salaf, like the attributions of al-Dimashqi (Damascene), al-Baghdadi (Baghdadi), al-Bazzar (the Cloth Merchant), and al-Qattan (the Cotton Merchant). Therefore, if the title "al-Muhajir" is not a specific family name in your place of residence, then there is no harm in attributing yourself to it.