rkhunter found this...

[brian]

Tom Horsley wrote:
> On Thu, 26 Mar 2009 14:40:06 -0700
> Daniel B. Thurman wrote:
> 
>> Looking @ /dev/nul:
>> =====================
>> # more /dev/nul
>> nsdc: no patch necessary.
>> =====================
>>
>> What does this mean?
> 
> It means some script somewhere did an rm -f on /dev/null
> then later some other script redirected output to /dev/null
> thus creating it as a regular file.
> 
It looks more like a typo, as another poster said (one L).