• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 751
  • Last Modified:

malicious computer program

A malicious computer program - perhaps a virus, I guess - informs a user that is hass "kidnapped" an important file and that what happens to the file will depend on the next statement typed by the user:

 - If the user types a false statement, the file will be deleted permanetly.

 - If the user types a true statement, the file will be randomly renamed and hidden in some obscured sub-directory, so that it can never be found and used again.

 - Failure to enter a statement would result in the deletion of that and many other files.

{Ignore the obvious problem of how the program can determine truth!}

Furthermore, the statement must fulfill several conditions. It must:

 - consist of a complete sentence [of any number of words];
 - be empirical [that is, it must refer to observable, measurable reality];
 - be related in some way to the program's threatened destructive or modification of the file.

The user typed a statement consisted with the condition listed above; the file was left unchanged, undeleted, with the same name.

What statement could the user have typed? [There are probably many statements which would work, differing in thier specific wording, but all recognizably members of the same family of statement.]


0
diddo143
Asked:
diddo143
  • 5
  • 5
  • 4
  • +5
1 Solution
 
WwysdomCommented:
This file will be deleted permanently.
0
 
HippyWarlockCommented:
Run Norton Ghost or similiar first, then just compare the two file listings, the extra file is yours - easy eh?

Peace
0
 
HippyWarlockCommented:
I assume the wastebin gets emptied too

Peace
0
 The Evil-ution of Network Security Threats

What are the hacks that forever changed the security industry? To answer that question, we created an exciting new eBook that takes you on a trip through hacking history. It explores the top hacks from the 80s to 2010s, why they mattered, and how the security industry responded.

 
HippyWarlockCommented:
Statement 1 : >The below statement is true.
Statement 2 : >The above statement is false.

cue infinite loop

Peace
0
 
ArcaArtemCommented:
Statement> You have kidnapped yourself you idoot!

0
 
WwysdomCommented:
As they used to say in the lounge...
Just fdisk and format.

d:D
0
 
☠ MASQ ☠Commented:
Logic bomb!

>>My important file will be deleted<<

If the deletion happens as a result then the statement is true and the virus cannot delete the file.  If the file is then renamed by the virus the statement becomes false.

If the file is not deleted the statement is false & the virus should have deleted the file but did not.
0
 
☠ MASQ ☠Commented:
(Points are Wwysdom's - they were in first!)
0
 
HippyWarlockCommented:
I'm still waiting for my loop to be resolved :-/

Peace
0
 
see201Commented:
The user unplugs the computer.  Problem solved!
0
 
see201Commented:
The user types the words "a statement".  As per the rules, failure to do otherwise will result in the deletion of that and many other files.  The important file will not be deleted because the user didn't type "a false statement", and it won't be renamed because the user didn't type "a true statement".
0
 
MercantilumCommented:
"You will delete my important file but not hide it in some obscured sub-directory!"
0
 
diddo143Author Commented:
Mercantilum, why would that work??? please explain.

See01, I thought the same thing but then I read on and your answer may vary so that answer really can't vary so I don't think that is right.

MASQUERAID, your explaination is very confusing it sounds like it makes sence but I am not sure if I am reading it right.

Wwysdom, please explain.

Thanks everyone for helping me out!!
0
 
☠ MASQ ☠Commented:
>>My important file will be deleted<<

It works because the virus follows a fixed logic.

If the statement is false then the file will be deleted.  But this would mean that the statement above becomes true.  The virus cannot action this.  Result inaction - the file is left alone.

If the statement is true the the file will not be deleted (moved instead).  But this would mean that the statement above becomes false.  The virus cannot action this.  result inaction - the file is left alone.
0
 
☠ MASQ ☠Commented:
@ HippyWarlock

^C
Break at line 210
>_

Now you can relax!
Hope this helps!

M :o)
0
 
WwysdomCommented:
Well, since dear MASQUERAID has explained it so well...
0
 
MercantilumCommented:
"You will delete my important file but not hide it in some obscured sub-directory!", explanation:

1. if it is false, the file should be deleted - but the sentance says "you will delete my important files", so if the file is deleted, the sentance was actually true
    => the sentance is not logically resolvable if it was said as false initially

2. if it is true, the file will be hidden, but the sentance says " not hide my file" so, again, it cannot be true either
    => the sentance is not logically resolvable if it was said as true initially

The virus attemps to do an action but it cannot assess the sentance as true, neither false.
So it does nothing.
0
 
WwysdomCommented:
This file will be deleted permanently.

If True, the virus should delete the file, but since the condition is that all true statements will result in the file being randomly hidden, this makes the statement false.

If False, the condition is that the file will be deleted permanently, but this will make the statement true, as it is correctly stated in the statement.

Since a sentence cannot be both true and false at the same time, the virus will not know what to do. At worst, it will just crash your whole system as it will use up all memory and resources in trying to find out which action to take.

PS. A small note: Both MASQUERAID's and Mercantilum's answers have the same logic, but their statements do not specifically refer to which file they refer to...

d:D
0
 
HippyWarlockCommented:
Chhers masq - I ran it on a Cray - it's well known that a corrctly configured HyperComputer can finish an infinite FOR-NEXT loop in just under an hour.


Peace
0
 
ozoCommented:
Why should we believe a malicious virus is telling the truth about what it's going to do with a file?
0
 
diddo143Author Commented:
I'm sorry guys I was going to spllit the points  but I messed up. Thank you for all your help.  Sorry again.
0
 
☠ MASQ ☠Commented:
0
 
diddo143Author Commented:
I'm sorry Wwysdom I was going to give you mostof the points and give MASQUERAID some and I thought you could split the points but I guess I messed up. I am really sorry about that.
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

  • 5
  • 5
  • 4
  • +5
Tackle projects and never again get stuck behind a technical roadblock.
Join Now