Bump_Rat

Overview

Bump-Rat is a specialized malware family that has drawn attention for its targeted application in cyber espionage campaigns. Unlike broadly distributed commodity malware, Bump-Rat is typically deployed post-compromise as a secondary payload, designed specifically to maintain a stealthy and persistent foothold within high-value networks. It is characterized by its lightweight architecture and modular design, allowing operators to deploy specific functional plugins as needed, thereby minimizing its overall footprint on the host system. Bump-Rat's primary functions include executing arbitrary shell commands, exfiltrating targeted documents, and mapping internal network topologies. To evade detection, it often utilizes uncommon communication protocols or piggybacks on legitimate network traffic, making it challenging for standard intrusion detection systems to flag. Analyzing Bump-Rat requires deep forensic capabilities and behavioral monitoring.

Known aliases

Threat reports may refer to this family under multiple names:

• BumpRAT

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: Visual_Basic_Rat_Framework

Known Derivatives & Downstream Variants: Bump_Rat_V2 · Trojan.Bumprat

MITRE ATT&CK Techniques

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

Tactical Mitigations

Based on the techniques used by this family, consider the following defensive strategies:

• T1059: Restrict execution of scripting languages such as PowerShell, VBScript, or Python to authorized administrators. Enforce Script Block Logging.
• T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.

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.

• e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8
• f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9

Delivery vectors

• Phishing lures mimicking commercial purchase orders and shipping invoices
• Social engineering attachments distributed via Discord and Telegram gaming groups

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\BumpRatServer
• Startup folder executable link '%APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup\bumprat.lnk'

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_BUMP_RAT_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Bump_Rat"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "bump_rat" ascii wide nocase
        $s2 = "bumprat" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Bump_rat (Trojan) Execution & Triage
id: 47544f4c-d323-57eb-b661-b048a4aa664c
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Bump_rat 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/bump_rat
- 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.t1059
- attack.t1048
- attack.t1046
- attack.t1105
- attack.t1090
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_BUMP_RAT_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Bump_Rat 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 = "bump_rat" 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 Bump Rat 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 Bump Rat installation.

References & External Analysis

• Malwarebytes Labs Threat Intelligence - Trojan.BumpRAT Analysis
• NIST National Vulnerability Database - CVE-2017-11882 Details
• Search "bump_rat" on VirusTotal (External Analysis)
• Search "bump_rat" on Any.Run (Sandbox Sandbox)
• Search "bump_rat" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Otorunq
• Generictka
• Keyboy
• Netshadow
• Hpcubestlr
• Ponmocup
• Indigorose
• Xxybvi

Machine-readable

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