Celesty

Overview

Celesty (often referenced as Celesty Binder or Celesty RAT) is a malicious utility designed to bundle multiple executable files together and facilitate remote backdoor access. As a binder, it takes a clean, legitimate host file (like a PDF reader or image viewer installer) and merges it with a hidden malicious payload. When the user executes the resulting hybrid file, both the legitimate application and the malware run simultaneously, heavily masking the malicious activity. The payload frequently dropped is the Celesty RAT, a feature-rich Remote Access Trojan capable of comprehensive system surveillance. The RAT can log keystrokes, manage files, manipulate the Windows Registry, and establish a persistence mechanism via the Startup folder or Run keys. Due to its dual nature as both a binder and a RAT, Celesty has been popular among amateur cybercriminals and script kiddies who rely on social engineering to trick victims into executing seemingly benign files.

Known aliases

Threat reports may refer to this family under multiple names:

• Celesty Binder
• Celesty RAT

Family Pedigree & Lineage

Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:

Derived From / Upstream Ancestry: Delphi_Binder_Rat_Framework

Known Derivatives & Downstream Variants: Celesty_V2.1 · Celesty_Binder

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:

MITRE D3FEND™ Defensive Countermeasures

Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):

Indicators of Compromise

Public indicators drawn from CISA advisories and vendor reporting. These are historical and intended for retrospective threat hunting; current campaigns may use different infrastructure. SystemHelpDesk adheres to responsible disclosure and does not host live samples.

File hashes (SHA-256, sample)

Cryptographic hashes serve as reference indicators for triage and detection rules. In accordance with responsible threat intelligence disclosure, this catalog indexes reference metadata and does not host or distribute live malware binaries.

• e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2
• f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3

Delivery vectors

• Trojanized game cracks and bundled executables combined using Celesty Binder
• Underground forum sharing and peer-to-peer file sharing networks

Persistence mechanisms

• HKLM\Software\Microsoft\Windows\CurrentVersion\Run\CelestyServer
• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\SystemTrayAgent

Tiered Detection Rules (Cisco CAIRN Model)

Modern threat detection requires multi-layered rule engineering. We classify detections into three operational tiers based on signal fidelity:

rule MALWARE_WIN_CELESTY_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Celesty"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "celesty" ascii wide nocase
        $s2 = "celesty binder" ascii wide nocase
        $s3 = "celesty rat" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Celesty (Trojan) Execution & Triage
id: e149d7a2-94cc-5655-ad83-f9def359f040
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Celesty malware family. Detects suspicious execution from temporary user
  directories with hidden window flags and background transfer utilities.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/celesty
- https://malware-families-catalog.systemhelpdesk.com/defensive/downloader-dropper-protection
- https://malware-families-catalog.systemhelpdesk.com/
author: Ricky Jordan, Lead Threat Intelligence Analyst, SystemHelpDesk MSP
date: '2026-10-14'
modified: '2026-10-14'
tags:
- attack.trojan
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1027_002
- attack.t1547_001
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \cmd.exe
    - \powershell.exe
    - \cscript.exe
    - \wscript.exe
    CommandLine|contains:
    - AppData\Local\Temp
    - -WindowStyle Hidden
    - /e:jscript
    - bitsadmin /transfer
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: medium

rule MALWARE_WIN_CELESTY_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Celesty tradecraft"
        tier = "T3 - Attribution Fingerprint"
        confidence = "High (Confirmed Family Signature)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        // Core family identifier & heuristic payload signatures
        $attrib_str = "celesty" ascii wide nocase
        $pe_magic = "MZ" ascii
        $net_marker = "http" ascii nocase
    condition:
        uint16(0) == 0x5a4d and ($attrib_str and $net_marker) and filesize < 15MB
}

Containment & Response Steps

Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.

1. Isolate affected endpoints from the network immediately to sever unauthorized command and control communication.
2. Identify and terminate active Celesty binaries and associated parent-child process chains.
3. Audit persistence vectors including Registry Run keys, Scheduled Tasks, and services for unauthorized entries.
4. Collect forensic disk and memory triage artifacts before conducting system re-imaging.

What to Avoid

Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.

1. Do not attempt manual string or file deletion while network connections remain active; this can trigger secondary dropper routines.
2. Avoid restoring from backups without verifying that the backup snapshot predates initial Celesty installation.

References & External Analysis

• Trend Micro Threat Encyclopedia - Backdoor.Win32.Celesty
• NIST National Vulnerability Database - CVE-2012-0158 Details
• Search "celesty" on VirusTotal (External Analysis)
• Search "celesty" on Any.Run (Sandbox Sandbox)
• Search "celesty" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Dynamer
• Gtbot
• Sinique
• Securityshield
• Comproc
• Netshadow
• Subseven
• Njlogger

Machine-readable

Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/celesty.json

Ecosystem & Interactive Environments

This profile is part of the Malware Families Catalog, a public dataset of 2,899 malware families. The catalog is also published across our ecosystem: Hugging Face, Kaggle, Zenodo, Replit, StackBlitz, CodeSandbox, and CodePen.