Ultimate attribution error
Explains the negative behaviors of outgroup(others) to personality defects and negative behaviors of the ingroup(us) to external circumstances or chance. Fundamental Attribution Error at group level.
It is most likely to happen to individuals who possess negative prejudices and stereotypes toward an outgroup.
This attribution is considered a root of prejudice, as people who commit this attribution will usually see members of other races, religions, cultures, or even social class as dispositionally inferior or flawed.