A bacteriophage, or phage, is a virus that infects bacteria. It injects genetic material into a bacterial cell, hijacks the cell’s machinery, and produces more phage particles. Because phages are highly specific to their bacterial hosts, they are widely studied in microbiology and antibacterial research.
In cyber security, phages matter because they sit at the center of modern biosecurity controls. AI systems that generate phage genomes can produce novel DNA sequences that may evade simple database matching, much like malware that avoids signature-based detection. That makes sequence screening, access control, logging, and human review important defenses. Phages are also a useful benchmark for safer biotechnology: they are generally studied outside human-pathogen space, but the same generative methods that design phage sequences could be misused if governance is weak. For security teams, phage work shows why prevention must be layered and adaptive, not based on static filters alone.