Alphanumeric shellcode: Difference between revisions

Revision as of 11:49, 24 April 2009

Revision as of 13:54, 6 May 2009

Line 5:

In general, in [[computing]], an '''alphanumeric code''' is a series of letters and numbers (hence the name) which are written in a form that can be processed by a computer.

In [[BSCS]] the alphanumeric character have meaning: "a"-"z", "A"-"Z", "0"-"9". No special characters are included.

Specifically, in computer underground terminology, alphanumeric code is [[machine code]] that is written so that it assembles into entirely alphanumeric [[ASCII]] characters such as 0-9, A-Z and a-z<ref>{{cite web |last=SkyLined |url=http://skypher.com/wiki/index.php?title=X86_alphanumeric_opcodes |title=List of x86 Alphanumeric opcodes |publisher=Skypher.com}}</ref><ref>{{cite web |last=SkyLined |url=http://skypher.com/wiki/index.php?title=X64_alphanumeric_opcodes |title=List of x64 alphanumeric opcodes |publisher=Skypher.com}}</ref>. This type of encoding was created by [[Hacker (computer security)|hackers]] to be able to pass machine code through a filter that removes any non-alphanumeric character and still be able to have it perform its intended tasks successfully. (Because normal machine code frequently uses non-alphanumeric characters, these would get removed by such a filter and the code would not be able to pass the filter without being modified to the point where it no longer works). A slightly less restrictive form of this type of encoding is printable code, which uses all [[Control character|printable]] characters such as 0-9, A-Z, a-z, !@#%^&*() etc...