Avast Free Antivirus Installer

Gen Digital Inc. (Avast Software)

Version: 2026 build (microstub + full installer)Binary: asw_sfx / microstubAnalyzed: 2026-02-11
F34/100

The Avast installer is significantly more aggressive than CCleaner (same parent). It integrates Google Analytics with a hardcoded API secret in plaintext, performs IP geolocation before consent, fires 5+ pre-consent network requests, and once installed deploys kernel-level DNS-over-HTTPS interception and deep packet inspection across 17 protocol handlers. The FTC fined Avast $16.5M in 2024 for selling 8+ petabytes of browsing data through its Jumpshot subsidiary.

15
Findings
9
critical
6
high
0
medium
0
low

Grade Breakdown

Weighted score: 34/100
Consent15/100 (25%)

5+ pre-consent network requests including IP geolocation and Google Analytics (third-party). No consent mechanism before data collection. Worst in category among analyzed software.

Data Minimization20/100 (20%)

Hardware fingerprinting via direct disk I/O, 200+ post-install tracking parameters, kernel-level network interception far exceeds what antivirus needs. 6 separate analytics endpoints.

Transparency30/100 (20%)

DNS interception and deep packet inspection not prominently disclosed. GA4 integration hidden. IP geolocation silent. FTC found prior lack of transparency.

Security60/100 (15%)

HTTPS for most endpoints but GA4 API secret hardcoded in plaintext (security risk). Kernel driver has proper signing. Transport encryption present but API secret exposure is concerning.

Policy Adherence10/100 (20%)

FTC already found Avast misrepresented data practices ($16.5M fine). Kernel DNS interception, DPI, and pre-consent tracking exceed policy disclosures. Binary behavior bears limited resemblance to stated practices.

Findings

Hardware Fingerprinting

high

Direct disk I/O for hardware serial numbers

avs-hw-001

Avast reads disk serial numbers via direct \\.\PhysicalDrive I/O (bypassing filesystem APIs) plus SystemUUID from SMBIOS and CPU ID from registry. The AcsSaveHardwareId function persists a composite fingerprint.

Evidence

AcsSaveHardwareId function. Direct access to \\.\PhysicalDrive0-3, \\.\Scsi%u:, SMBIOS Type 1 SystemUUID, HARDWARE\DESCRIPTION\System\CentralProcessor\0.

Kernel Interception

critical

Kernel-level DNS-over-HTTPS interception (DohMode=3)

avs-kern-001

Once installed, Avast deploys a kernel driver that intercepts encrypted DNS queries. DohMode=3 (most aggressive) targets cloudflare-dns.com and dns.google. If you configure Windows to use encrypted DNS for privacy, Avast decrypts every query at the kernel level.

Evidence

DohMode=3, DohSystemEnabled=1. Targets: cloudflare-dns.com/dns-query, dns.google/dns-query. Overrides system DoH settings.

critical

Deep packet inspection across 17 protocol handlers

avs-kern-002

The Avast Stream Filter kernel driver (aswSP.sys) monitors all internet traffic through 13 TCP handlers (HTTP, HTTP/2, SSL, WebSocket, RDP, etc.) and 4 UDP handlers (DNS, QUIC, SecureDns, Antiphishing).

Evidence

TCP handlers: Connect, DataTheft, DnsCache, Http1x, Http2x, InnerDump, OuterDump, Rdp, SecureDns, Spdy, Ssl, SslCertRep, TinyFw, Websocket. UDP: Antiphishing, DnsCache, Quic, SecureDns.

Analytics & Third-Party

critical

Google Analytics GA4 with hardcoded API secret in plaintext

avs-ga-001

Avast integrates Google Analytics 4 with measurement ID G-WZQ6MQ6RF3 and API secret YQldHTFNQhK9FZrFOXa3Lw hardcoded in the binary in plaintext. This sends installation telemetry to Google before user consent.

Evidence

POST https://www.google-analytics.com/mp/collect?measurement_id=G-WZQ6MQ6RF3&api_secret=YQldHTFNQhK9FZrFOXa3Lw. Universal Analytics: UA-58120669-3.

Tracking & Identifiers

high

5 pre-embedded tracking identifiers baked into binary

avs-track-001

The binary contains hardcoded tracking IDs: gdid (Global Device ID: 4ac436c9-...), clid (Google Analytics-style: 1183318856.1770780902), seid (Unix timestamp), senu (session counter), and marketing cookie (mmm_ava_tst_999_402_m).

Full evidence available at researcher tier — sign in

Browser Tracking

high

Chrome browser tracking keys and extension force-install

avs-browser-001

Avast writes Google RLZ partner attribution keys to Chrome's registry and force-installs the Avast Online Security browser extension via registry manipulation.

Full evidence available at researcher tier — sign in

Telemetry

high

200+ In-Product Messaging parameters tracked continuously

avs-ipm-001

Post-install, Avast's config.def reveals 200+ client parameters tracked for ad/upsell targeting: license state, feature usage, browser data, device info, account state, and behavioral patterns.

Full evidence available at researcher tier — sign in

Network Endpoints

high

6 separate analytics/tracking endpoints

avs-net-001

Avast uses six separate tracking systems: (1) Google Analytics GA4, (2) Gen Digital Burger Analytics, (3) Avast Event Telemetry, (4) Avast Statistics, (5) IP Geolocation, (6) Shepherd A/B Testing.

Evidence

Endpoints: google-analytics.com, analytics.avcdn.net/v4/receive/json/70, v7event.stats.avast.com, v7.stats.avast.com, ip-info.ff.avast.com, shepherd.ff.avast.com.

GDPR / Privacy Regulation

critical

GDPR Art. 6 — 5+ pre-consent requests including third-party data sharing

avs-gdpr-001

At least 5 network requests fire before user consent, including one to Google (GA4) which constitutes international data transfer to a third party. No lawful basis established.

Evidence

Phase 1: IP geolocation, GA4 event (to Google servers), Shepherd request, marketing cookie, hardware fingerprint. All before Phase 2 UI.

critical

ePrivacy Art. 5 — Kernel DNS interception breaks communication confidentiality

avs-gdpr-002

Intercepting and decrypting DNS-over-HTTPS queries at the kernel level violates the confidentiality of communications that users explicitly encrypted by configuring DoH.

Evidence

DohMode=3 intercepts cloudflare-dns.com and dns.google DoH queries. DohSystemEnabled=1 overrides user's explicit encrypted DNS configuration.

Regulatory Actions

critical

FTC fined Avast $16.5M for selling browsing data (2024)

avs-ftc-001

The FTC found that Avast collected 8+ petabytes of browsing data from 2014-2020 and sold it to 100+ third parties through its Jumpshot subsidiary. Data revealed religious beliefs, health concerns, political leanings, and financial status at individual session granularity.

Evidence

FTC v. Avast (2024). Fine: $16.5M. Period: 2014-2020. Jumpshot shut down January 2020. Technical capability for data collection remains in 2026 codebase.

high

FTC findings still present in 2026 codebase

avs-ftc-002

Key FTC findings from 2014-2020 remain in the 2026 build: browser extensions force-installed, pre-consent telemetry, persistent device tracking, browsing behavior observation (now expanded with kernel DNS/HTTPS interception), and third-party data sharing via Google Analytics.

Evidence

Comparison table: Browser extension force-install (still present), pre-consent telemetry (still present), persistent device tracking (still present), browsing observation (expanded: kernel DoH+DPI), third-party sharing (GA still active).

Policy Adherence

critical

Binary behavior materially exceeds policy disclosures

avs-policy-001

Kernel-level DNS interception, deep packet inspection across 17 protocols, hardcoded Google Analytics API secret, and pre-consent IP geolocation are not prominently disclosed. The FTC already found Avast misrepresented data practices (2024 enforcement).

Evidence

DohMode=3 not in installer disclosure. GA4 API secret in plaintext. IP geolocation pre-consent. FTC found prior misrepresentation. Policy adherence: poor.

Methodology

Static analysis via Ghidra decompilation of microstub and asw_sfx PE32 binaries (17,555 functions). RTTI class recovery. String extraction. Cross-reference with CCleaner analysis (same asw:: framework). FTC enforcement data from public filings.

Compare with other software

See how this product's data practices compare side-by-side.

View Comparison