Stream cipher Hiji-Bij-Bij (HBB) was proposed by Sarkar at Indocrypt’03. This cipher uses cellular automata (CA). The algorithm has two modes: a basic mode (B) and a self-synchronizing mode (SS). This article presents the first attack on B mode of HBB using 128 bit secret key. This is a known-pliantext guess-then-determine attack. The main step in the attack guesses 512 bits of unknown out of the 640 bits of the initial internal state. The guesses are done sequentially and the attack uses a breadth-first-search-type algorithm so that the time complexity is 250 .