Xiclog
Table of Contents
Overview
Xiclog (cataloged across security vendors and threat intelligence databases under signatures including Backdoor:Win32/Xiclog, Trojan:Win32/Xiclog, and Backdoor.Xiclog) is a persistent Windows remote access trojan (RAT) and backdoor active since 2017. Delivered primarily through spearphishing emails with malicious attachments, weaponized Office documents, and drive-by exploit kits, Xiclog operates covertly to provide adversaries with interactive access. Upon execution, Xiclog establishes startup persistence via Windows scheduled tasks and Registry Run entries. It injects its malicious threads into legitimate system processes like svchost.exe to conceal outbound network traffic, connecting to remote C2 infrastructure over encrypted HTTP/HTTPS to execute arbitrary shell commands, harvest system telemetry, and drop secondary payloads.
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/Xiclog.A · Trojan:Win32/Xiclog!Rfn
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1059.003 · T1055 · T1547.001 · T1105 · T1071.001 · T1082
Tactical Mitigations
Based on the techniques used by this family, consider the following defensive strategies:
- T1059.003: Restrict execution of Windows Command Shell (cmd.exe) and block unauthorized batch scripts.
- 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.
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-PIAD | Process Injection Analysis & Detection | Detect | T1055 | Monitor cross-process thread creation (CreateRemoteThread) and asynchronous procedure calls (QueueUserAPC). |
D3-PBA | Process Spawn Analysis | Detect | T1059.003 | Inspect command-line arguments and anomalous parent-child relationships spawning from cmd.exe. |
D3-WAF | Web Content Filtering & Inspection | Filter | T1071.001 | Block newly registered domains (NRDs) and inspect HTTP Host and URI headers for known C2 profiles. |
D3-SDA | System Discovery Analysis | Detect | T1082 | Alert on rapid enumerations of systeminfo, hostname, and registry hardware trees in short intervals. |
D3-NTI | Network Traffic Inspection | Detect | T1105 | Inspect deep packet payloads for anomalous staging binaries and unauthorized egress protocols. |
D3-RPM | Registry Persistence Monitoring | Detect | T1547.001 | Audit and restrict write privileges to user and machine-level Registry Run/RunOnce keys using Endpoint Privilege Management. |
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_XICLOG_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Xiclog"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "xiclog" ascii wide nocase
$s2 = "backdoor:win32/xiclog" ascii wide nocase
$s3 = "trojan:win32/xiclog" ascii wide nocase
$s4 = "backdoor.xiclog" ascii wide nocase
$s5 = "win32/xiclog" ascii wide nocase
$s6 = "backdoor:win32/xiclog.a" 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 - Xiclog (Backdoor) Execution & Triage
id: dd8bdb61-6d6d-5f19-b387-c7b1ab5b52db
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Xiclog 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/xiclog
- 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.t1059_003
- attack.t1055
- attack.t1547_001
- attack.t1105
- attack.t1071_001
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_XICLOG_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Xiclog 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 = "xiclog" 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
- Microsoft Defender Threat Encyclopedia - Backdoor:Win32/Xiclog
- Search "xiclog" on VirusTotal (External Analysis)
- Search "xiclog" on Any.Run (Sandbox Sandbox)
- Search "xiclog" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Backdoor:Win32/Xiclog?
Xiclog is a persistent Windows remote access trojan that grants attackers interactive command execution over infected endpoints.
How do attackers distribute Xiclog to victims?
Through spearphishing emails containing malicious document attachments and drive-by download exploit kits.
How does Xiclog conceal its network communications?
It injects its core communication modules into legitimate Windows system processes such as svchost.exe.
What remote capabilities are provided by Xiclog?
It allows operators to run command prompt commands, upload/download files, capture system info, and stage secondary malware.
How can incident responders remediate a Xiclog compromise?
Perform a Microsoft Defender Offline scan, terminate injected svchost processes, audit scheduled tasks, and reset credentials.
How do I remove the Xiclog Backdoor from Windows?
Manual removal of Xiclog 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 Xiclog a virus or a Backdoor?
Xiclog is classified as a Backdoor. Unlike traditional viruses that infect files, modern malware like Xiclog typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Xiclog infection?
Symptoms of Xiclog 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 Xiclog 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/xiclog.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.