Backstabber is a scanner with a fixed-length attack which entered the Intel 88 hill in April 1993 and survived 316+ challenges before being pushed off in June. Backstabber also entered the EBS Summer Tournament 93.

;name Backstabber
;author Anders Ivner
;strategy Brief scanner.

; Oh well, I don't know. I guess this one has as much chance as anything
; else.

dist    equ     19
step    equ     3094

start   add     const,          scan
scan    cmp     -dist,          0
        slt     #20+dist,      scan
        jmp     start

        mov     #19+dist,       cnt
        mov     scan,           @loop
loop    mov     glue,           <scan+11
cnt     djn     loop,           #0
        djn     start,          #20		;how many times?

	spl     0,		<-3
clr2    mov     gate,           <-2
	jmp	-1,		<-5
	dat		#0
gate	dat	<-4,		<-5
const   dat     #step,          #step
glue	spl	-1,		1

	end	start