Well, that is what the anti-communist propaganda claimed, but I do not think there is much truth in it. I mean there probably were individuals who joined the security forces with ulterior motives, but these were isolated incidents that do not mean anything. As far as I can tell, the post-communist right wingers were able to come up with one name of an ex security officer who fled to Israel. One name is all they could get!
Based on the empirical studies of the Jewish attitudes between 1947 and 1950 that I am familiar with, the prevailing attitude was that of fear, exacerbated by incidents such as the Kielce pogrom of 1946, disillusionment, and alienation. People were talking not about avenging the death of their brethren or their past discrimination, but about either leaving for Palestine, or put hopes in the new system - which indeed open new opportunities, especially civil service, for the Jewish population. Many Jews indeed worked for the government, which prompted the detractors of the socialist system to label it "judeo-communism" - but I am not aware of any acts of "Jewish revenge" which strikes me as a product of the right wing propaganda.
Wojtek