Assumptions & Evaluations
Description of keywords, operators, pseudo-registers, number prefixes, and pre-defined functions
The following articles describe HyperDbg's Script Engine.
HyperDbg uses a MASM-like (Windbg) syntax to evaluate script expressions.
HyperDbg script engine is case-sensitive.
The following keywords are valid in Script Engine.
Keyword | Description |
|---|---|
poi | Pointer-sized data from the specified address (dereference) |
ref | Reference address of the specified variable |
hi | High 16 bits (dereference) |
low | Low 16 bits (dereference) |
db | Low 8 bits (dereference) |
dd | Low 16 bits (dereference) |
dw | Low 32 bits (dereference) |
dq | 64 bits (dereference) |
not | Flip each and every bit |
neg | True/False logic flipping |
The following operators are supported on the script engine.
Operator | Description |
|---|---|
( ) | Parentheses |
- + ~ * & | Unary Operators (Unary negative, Unary positive, Bitwise not, Reference, Address of) |
/ % * | Arithmetic Operators (Division, Modulo, Multiplication) |
+ - | Arithmetic Operators (Addition, Subtration) |
<< >> | Shift Operators (Right shift, Left shift) |
& | Bitwise AND Operator |
^ | Bitwise XOR Operator (exclusive OR) |
| | Bitwise OR Operator |
Operator | Description |
|---|---|
( ) | Parentheses |
- + ~ * & | Unary Operators (Unary negative, Unary positive, Bitwise not, Reference, Address of) |
/ % * | Arithmetic Operators (Division, Modulo, Multiplication) |
+ - | Arithmetic Operators (Addition, Subtration) |
<< >> | Shift Operators (Right shift, Left shift) |
>= < > <= == != | Comparison operators |
& | Bitwise AND Operator |
^ | Bitwise XOR Operator (exclusive OR) |
| | Bitwise OR Operator |
&& | Logical AND |
|| | Logical OR |
The following registers are supported by HyperDbg.
Registers | Description |
|---|---|
@rax @eax @ax @ah @al @rcx @ecx @cx @ch @cl @rdx @edx @dx @dh @dl @rbx @ebx @bx @bh @bl @rsi @esi @si @sil @rdi @edi @di @dil | General-purpose registers |
@r8 @r8d @r8w @r8h @r8l @r9 @r9d @r9w @r9h @r9l @r10 @r10d @r10w @r10h @r10l @r11 @r11d @r11w @r11h @r11l @r12 @r12d @r12w @r12h @r12l @r13 @r13d @r13w @r13h @r13l @r14 @r14d @r14w @r14h @r14l @r15 @r15d @r15w @r15h @r15l | 64-bit mode registers |
@rsp @esp @sp @spl @rbp @ebp @bp @bpl | Stack management registers |
@rip @eip @ip | Program counter (Instruction pointer) |
@rflags @eflags @flags | Flags register |
@ds @es @cs @ss | Segment registers |
@fs @gs | Segment registers (80386) |
@cr0 @cr2 @cr3 @cr4 @cr8 | Control registers |
@gdtr @ldtr @tr | Memory management registers |
@idtr | Interrupt descriptor register |
@dr0 @dr1 @dr2 @dr3 @dr6 @dr7 | Debug registers |
Model-/machine-specific registers (MSRs) |
Each flag of RFLAGS is also supported in HyperDbg.
Bit # | Mask | Register Abbreviation | Description | Category |
FLAGS | | | | |
0 | 0x0001 | @cf | Carry flag | Status |
1 | 0x0002 | _ | Reserved, always 1 in EFLAGS | _ |
2 | 0x0004 | @pf | Parity flag | Status |
3 | 0x0008 | _ | Reserved | _ |
4 | 0x0010 | @af | Adjust flag | Status |
5 | 0x0020 | _ | Reserved | _ |
6 | 0x0040 | @zf | Zero flag | Status |
7 | 0x0080 | @sf | Sign flag | Status |
8 | 0x0100 | @tf | Trap flag (single step) | Control |
9 | 0x0200 | @if | Interrupt enable flag | Control |
10 | 0x0400 | @df | Direction flag | Control |
11 | 0x0800 | @of | Overflow flag | Status |
12-13 | 0x3000 | @iopl | I/O privilege level (286+ only), always 1 on 8086 and 186 | System |
14 | 0x4000 | @nt | Nested task flag (286+ only), always 1 on 8086 and 186 | System |
15 | 0x8000 | _ | Reserved, always 1 on 8086 and 186, always 0 on later models | _ |
EFLAGS | | | | |
16 | 0x0001 0000 | @rf | Resume flag (386+ only) | System |
17 | 0x0002 0000 | @vm | Virtual 8086 mode flag (386+ only) | System |
18 | 0x0004 0000 | @ac | Alignment check (486SX+ only) | System |
19 | 0x0008 0000 | @vif | Virtual interrupt flag (Pentium+) | System |
20 | 0x0010 0000 | @vip | Virtual interrupt pending (Pentium+) | System |
21 | 0x0020 0000 | @id | Able to use CPUID instruction (Pentium+) | System |
22‑31 | 0xFFC0 0000 | _ | Reserved | System |
RFLAGS | | | | |
32‑63 | 0xFFFF FFFF… 0000 0000 | Reserved | _ | _ |
Here are the currently supported pseudo-registers supported by the script engine.
Pseudo-register | Description |
|---|---|
$pid | The process ID (PID) of the current process. |
$proc | The address of the current process (that is, the address of the nt!_EPROCESS block). |
$pname | A pointer to the character array of the process name. (It is a 16-byte long array in kernel-mode). |
$tid | The thread ID for the current thread. |
$core | The core ID for the current core. |
$thread | The address of the current thread. In kernel-mode debugging, this address is the address of the nt!_ETHREAD block. |
$peb | The address of the process environment block (PEB) of the current process. |
$teb | The address of the thread environment block (TEB) of the current thread. |
$ip | The instruction pointer register (rip). |
$buffer | The pre-allocated buffer if the user requests a safe buffer. |
$context | The context of the triggered event (It has a different meaning in each event). |
$event_id | The event ID of the triggered event (Only in the case of events). [Added from v0.2] |
$event_tag | The event tag of the triggered event (Only in the case of events). [Added from v0.2] |
Some of the above pseudo-registers are not supported either in kernel-mode or user-mode. If you use these registers, then it returns
NULL.By default, HyperDbg interprets the numbers as hex (base 16). If you want to specify other forms of a number, you should use MASM prefixes. In all MASM expressions, numeric values are interpreted as numbers in the current radix (16, 10, or 8). You can override the default radix by specifying the 0x prefix (hexadecimal), the 0n prefix (decimal), the 0t prefix (octal), or the 0y prefix (binary).
HyperDbg's comments are like C comments.
A comment starts with a slash asterisk
/* and ends with an asterisk slash */ and can be anywhere in your program. Comments can span several lines within your C program./* comment goes here */
OR
/*
* comment goes here
*/
You can create a comment on a single line.
// comment goes here
Last modified 8mo ago