Smallhttp

Overview

HackTool:Win32/Smallhttp refers to highly compact, portable web server executables that are frequently dropped onto compromised machines by attackers during post-exploitation. While web servers are legitimate software, attackers use 'Smallhttp' utilities because they require no installation, leave minimal footprint, and can be instantly bound to a port to facilitate rapid data exfiltration (`T1041`) or internal payload staging for lateral movement.

Understanding Smallhttp (Staging and Exfiltration)
To an end-user, there is no visible impact. For a SOC analyst, the presence of an unexpected HTTP server running on an endpoint (especially a workstation) is a massive red flag. It indicates the attacker has bypassed initial defenses and is now establishing an internal staging area to move deeper into the network or preparing to steal large volumes of data.

Execution and Exploitation Mechanics
After gaining a shell on a machine (e.g., via a spearphishing macro or RDP brute force), the attacker drops a tiny HTTP server executable (often only a few kilobytes in size) into a hidden directory. They execute it via the command line, pointing it to a directory containing stolen data (like ZIP files of documents) (`T1560`). The attacker can then simply use `curl` or `wget` from another compromised machine (or externally, if the firewall allows) to download the stolen data over standard port 80/8080, masking the exfiltration as normal web traffic (`T1071.001`).

Indicators of Compromise & Impact
The impact is usually significant data loss or the facilitation of lateral movement. Host-based IoCs include EDR alerts for unknown executables binding to network ports (listening state) on workstations. Look for processes like `svchost.exe` or `cmd.exe` spawning an unknown binary with command-line arguments specifying a port and directory path. Network IoCs include a sudden spike in outbound HTTP GET requests originating *from* the compromised workstation to external IPs, or unusual internal HTTP traffic between workstations.

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to the MITRE ATT&CK framework:

Tactical Mitigations

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

• T1071.001: Implement web filtering and SSL/TLS inspection to detect malicious command and control (C2) traffic hiding in HTTP/HTTPS.
• T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.

Generated Detections (Boilerplate)

These YARA and Sigma rules are auto-generated based on the family name and aliases. They must be heavily tuned before deployment in a production environment.

YARA Rule

rule MALWARE_WIN_SMALLHTTP {
    meta:
        description = "Detects Smallhttp (advanced_threat)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "smallhttp" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Smallhttp Activity
id: 430a8d0b99daf0bf947abfe4019fbc36
status: experimental
description: Detects generic indicators of the smallhttp malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*smallhttp*"
    condition: selection
level: medium

Containment & Response Steps

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

1. Isolate the endpoint immediately; if the server is running, the attacker is actively moving data.
2. Use `netstat -ano` or EDR tools to identify the specific process bound to the HTTP port and terminate it.
3. Identify the directory the Smallhttp server was serving to determine exactly what data the attacker was exfiltrating.
4. Review internal network flows to see if other endpoints downloaded payloads *from* this staging server.

What to Avoid

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

1. Do not simply kill the process and move on; you must investigate what files were in the web root to understand the scope of the breach.
2. Avoid relying solely on external firewall logs; if the attacker used the server for internal lateral movement, the traffic never left the network.

References & External Analysis

• Search "smallhttp" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: advanced_threat)

Explore other malware families in the same category:

• Cnsmin
• Openshopper
• Iwin
• Rustock
• Pcacceleratepro

Machine-readable

Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/api/smallhttp.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.