A series of activated iodo-benzamide derivatives are described as antineoplastic and antiviral drug compounds. The compounds generally possess a chelating group, a thiol trapping group and an activating group. The presumptive mechanism of action in preventing cancer cell and virus replication is through inhibition of the binding of transcription factors to zinc finger binding domains. The compounds are effective in inhibiting growth of a variety of human and animal tumor and leukemia cell lines at low concentrations.