Learning Malware Analysis

6.5 If-Elseif-Else Statement

The following is a C code containing if-ElseIf-else statements:

if (x == 0) {  x = 5;}else if (x == 1) {  x = 6;}else {  x = 7;}

From the preceding code, let's try to determine a situation when jumps (control transfers) will be taken. There are two conditional jump points; if x is not equal to 0, it will jump to the else_if block, and if x is not equal to 1 (a condition check in else if), then the jump is taken to else. There are also two unconditional jumps: inside the if block after x=5 (the end of the if block) and inside of the else if after x=6 (the end of the else if block). Both of these unconditional jumps skip the else statement to reach the end.

The following is the translated assembly language showing ...