ICE 0xF1

ICEBP is an undocumented instruction that serves as a single byte interrupt 1, generating a single step exception. It can be used to detect if the program is traced.

Technique Identifier

U0130

Technique Tags

0xf1 icebp

Featured Windows API's

Below, you will find a list of the most commonly used Windows API's that are currently utilized by malware authors for current evasion technique. This list is meant to provide an overview of the API's that are commonly used for this purpose. If there are any API's that you feel should be included on this list, please do not hesitate to contact us. We will be happy to update the list and provide any additional information or documentation that may be helpful.

IsDebuggerPresent

Evasion Categories

Anti-Debugging

Code Snippets

BOOL IsDebuggerPresent_IceBp()
{
    __try
    { 
        __asm __emit 0xF1 
    }
    __except(1) 
    { 
        return FALSE; 
    }
    return TRUE;
}

About Author Open Snippet

Author: External / Target Platform: Windows

Detection Rules

rule Detect_Interrupt: AntiDebug {
    meta: 
        description = "Detect Interrupt instruction"
        author = "Unprotect"
        comment = "Experimental rule / the rule can be slow to use"
    strings:
        $int3 = { CC }
        $intCD = { CD }
        $int03 = { 03 }
        $int2D = { 2D }
        $ICE = { F1 }
    condition:   
       uint16(0) == 0x5A4D and filesize < 1000KB and any of them
}

rule:
  meta:
    name: execute anti-debugging instructions
    namespace: anti-analysis/anti-debugging/debugger-detection
    authors:
      - moritz.raabe@mandiant.com
    scope: function
    mbc:
      - Anti-Behavioral Analysis::Debugger Detection::Anti-debugging Instructions [B0001.034]
    examples:
      - Practical Malware Analysis Lab 16-03.exe_:0x401300
  features:
    - or:
      - count(mnemonic(rdtsc)): 2 or more
      - mnemonic: icebp

Contributor

Thomas Roccia (fr0gger)

Matching Samples 10 most recent

Sample Name	Matching Techniques	First Seen	Last Seen
2_5339247083163523934.exe	6	2026-03-27	2 days, 19 hours ago
rootkit.exe	10	2026-03-24	5 days, 17 hours ago
spread.exe	6	2026-03-24	5 days, 17 hours ago
ngen.exe	7	2026-03-20	1 week, 3 days ago
write.exe	5	2026-03-20	1 week, 3 days ago
UnPackMe_VMProtect_1.53.exe	7	2026-03-19	1 week, 4 days ago
loader.exe	5	2026-03-14	2 weeks, 1 day ago
BBHloader.exe	6	2026-03-10	2 weeks, 5 days ago
library2.dll	6	2026-03-06	3 weeks, 2 days ago
library.dll	8	2026-03-06	3 weeks, 2 days ago

View All

Created

June 22, 2022

Last Revised

March 24, 2026