Pterodo
Table of Contents
Overview
Pterodo (also known as Pteranodon, tracked under designations including Backdoor:Win32/Pterodo, Trojan:Win32/Pterodo, and Backdoor.Pteranodon) is a specialized cyber espionage backdoor and reconnaissance framework actively developed and operated by the Russian state-sponsored advanced persistent threat actor Gamaredon (Primitive Bear, ACTINIUM, Shuckworm, UAC-0010) since at least 2014. Exclusively deployed in targeted campaigns against Ukrainian governmental, military, law enforcement, and critical infrastructure organizations, Pterodo is distributed via spear-phishing emails containing malicious Microsoft Office documents with weaponized VBA macros or dynamic remote template injection. Once executed, Pterodo drops multi-stage VBScript, AutoIt, or PowerShell payloads. It gathers extensive system enumeration telemetry (machine name, volume serial numbers, network adapters, and security software), establishes persistence via scheduled tasks and user Startup folder shortcuts, and communicates with dynamically rotating fast-flux C2 infrastructure. Pterodo's modular design enables operators to download secondary modules, capture screenshots, log keystrokes, and exfiltrate sensitive strategic military files.
Known aliases
Threat reports may refer to this family under multiple names:
Family Pedigree & Lineage
Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:
Known Derivatives & Downstream Variants: Backdoor:Win32/Pterodo.A · Backdoor:Win32/Pterodo.B · Trojan:Vbs/Pterodo
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1566.001 · T1059.005 · T1053.005 · T1568.002 · T1082 · T1113
Tactical Mitigations
Based on the techniques used by this family, consider the following defensive strategies:
- T1059.005: Restrict execution of scripting languages such as PowerShell, VBScript, or Python to authorized administrators. Enforce Script Block Logging.
- T1113: Monitor for frequent or unauthorized screen captures or clipboard reads. Restrict background applications from accessing desktop APIs.
- T1566.001: Scan email attachments for malicious macros, scripts, or suspicious archive files.
MITRE D3FEND™ Defensive Countermeasures
Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):
| D3FEND ID | Countermeasure Name | Tactic | Countered ATT&CK | Defensive Guidance |
|---|---|---|---|---|
D3-STM | Scheduled Task Creation Analysis | Detect | T1053.005 | Audit task creation targeting system and hidden service directories; verify task author credentials. |
D3-SEA | Script Execution Analysis | Detect | T1059.005 | Analyze script block syntax and command arguments at runtime to detect malicious automation. |
D3-SDA | System Discovery Analysis | Detect | T1082 | Alert on rapid enumerations of systeminfo, hostname, and registry hardware trees in short intervals. |
D3-SD | Screen Capture Detection | Detect | T1113 | Monitor desktop graphics API calls (BitBlt, GetDC) triggered by non-standard background threads. |
D3-FS | File Sandboxing (Attachment Detonation) | Isolate | T1566.001 | Detonate macro-enabled documents, ISOs, and password-protected archives inside an isolated hypervisor. |
D3-DNSR | DNS Reputation Analysis | Detect | T1568.002 | Deploy recursive DNS security resolvers with algorithmic domain scoring (entropy and n-gram models) to automatically sinkhole DGA queries. |
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:
Tier 1 Primitive Artifact Rule (Fast Triage)
Matches raw strings and file markers. Vulnerable to binary repacking and simple obfuscation.
rule MALWARE_WIN_PTERODO_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Pterodo"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "pterodo" ascii wide nocase
$s2 = "backdoor:win32/pterodo" ascii wide nocase
$s3 = "trojan:win32/pterodo" ascii wide nocase
$s4 = "backdoor.pteranodon" ascii wide nocase
$s5 = "win32/pteranodon" ascii wide nocase
$s6 = "pteranodon rat" ascii wide nocase
$s7 = "gamaredon pterodo" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Tier 2 Behavioral Context Rule (Process Chains & Sigma)
Tracks parent-child process anomalies and suspicious scripting telemetry. Resilient against file renames.
title: SystemHelpDesk Detection - Pterodo (Backdoor) Execution & Triage
id: 1a7ed195-ba15-582a-bb65-055cd53430ba
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Pterodo malware family. Detects proxy execution, reflective DLL loading,
and remote command injection associated with modular enterprise backdoors.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/pterodo
- https://malware-families-catalog.systemhelpdesk.com/defensive/backdoor-rat-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.backdoor
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1566_001
- attack.t1059_005
- attack.t1053_005
- attack.t1568_002
- attack.t1082
logsource:
category: process_creation
product: windows
detection:
selection_process:
Image|endswith:
- \powershell.exe
- \cmd.exe
- \rundll32.exe
- \regsvr32.exe
CommandLine|contains:
- DownloadString
- IEX(
- '/s /n /u /i:'
- sc create
- start-process
condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: highTier 3 Attribution Fingerprint Rule (High Fidelity)
Deep signature matching distinctive operational fingerprints and payload characteristics.
rule MALWARE_WIN_PTERODO_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Pterodo 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 = "pterodo" 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
}References & External Analysis
- CISA Alert AA22-047A - Russian State-Sponsored Cyber Threats to Critical Infrastructure
- Microsoft Threat Intelligence - ACTINIUM (Gamaredon) Targets Ukrainian Organizations
- CERT-UA Advisory - UAC-0010 (Gamaredon) Malicious Activity
- CISA Advisory: AA22-047A
- Search "pterodo" on VirusTotal (External Analysis)
- Search "pterodo" on Any.Run (Sandbox Sandbox)
- Search "pterodo" on MalwareBazaar (Malware Samples)
North American Authority Advisory (CISA / NIST)
The Cybersecurity and Infrastructure Security Agency (CISA) has published an official US federal advisory on this family, which can be mapped to NIST Cybersecurity Framework (CSF) incident response controls: AA22-047A ↗
Frequently Asked Questions
What is Backdoor:Win32/Pterodo?
Pterodo is a cyber espionage backdoor developed and used by the Russian state-sponsored threat group Gamaredon.
Which threat actor operates the Pterodo backdoor?
It is operated by Gamaredon Group (also known as Primitive Bear, ACTINIUM, Shuckworm, and UAC-0010).
How does Pterodo infect victim computers?
It is delivered through spear-phishing emails delivering malicious Office attachments with VBA macros or remote template injection.
What are Pterodo's primary espionage capabilities?
It performs endpoint reconnaissance, captures screenshots, downloads secondary plugins, and exfiltrates strategic government and military files.
How does Pterodo maintain persistent access across reboots?
It creates Windows Scheduled Tasks and drops malicious shortcut (.lnk) files into the Startup directory.
How do I remove the Pterodo Backdoor from Windows?
Manual removal of Pterodo is highly discouraged as it may leave persistence mechanisms intact. We recommend disconnecting the device from the internet and utilizing a professional incident response service or enterprise-grade EDR software to conduct a full forensic sweep.
Is Pterodo a virus or a Backdoor?
Pterodo is classified as a Backdoor. Unlike traditional viruses that infect files, modern malware like Pterodo typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Pterodo infection?
Symptoms of Pterodo can include unexpected system slowness, unauthorized outbound network traffic to unknown IP addresses, disabled security software, and suspicious background processes running from AppData or Temp directories.
Protect Your Network Against Backdoors
Want to prevent Pterodo and similar threats from compromising your organization? Read our comprehensive defensive guide: Backdoor & RAT Protection for Businesses.
📣 Threat Intel Correction or Update?
Notice an outdated IOC, unlisted alias, or disputed attribution? Threat researchers are invited to propose an update on GitHub or contact the SystemHelpDesk research desk. All community revisions are credited in our public CHANGELOG.
Machine-readable
Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/pterodo.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.