LeechModem was a BBS file transfer protocol client. LeechModem was compatible with protocols like XMODEM (and YMODEM), but it would mischievously NAK the last packet and then abort the file transfer.
LeechModem was a BBS file transfer protocol client that used protocols like XMODEM (and YMODEM). It would maliciously fail to transmit the last packet and then terminate the file transfer.