Internal Research Report: Acronis Authentication Flow and Failure‑Mode Analysis

Author: Stephen Fasciani
Date: February 11, 2026
Audience: Engineering, Cloud Operations, Security

1. Overview

This document summarizes the findings from a hands‑on investigation into Acronis’ authentication workflow, including session initialization, credential validation, MFA handling, and network‑based access restrictions. The goal of this research was to understand the underlying mechanics of the login process well enough to build deterministic, cross‑platform automation without relying on browser automation or UI scraping.

The work resulted in a validated, hardened login proof‑of‑concept (POC) implemented in both PowerShell and Python. This POC demonstrates that Acronis authentication can be performed programmatically with predictable behavior and clear failure‑mode detection.

2. Background and Motivation

Historically, internal automation around Acronis has relied on Selenium‑based browser automation to extract configuration values and enforce security posture (e.g., ensuring Access Control remains VPN‑restricted). While functional, this approach is:

• brittle (UI changes break selectors)

• slow (browser startup overhead)

• platform‑dependent

• difficult to deploy in headless Linux environments

• harder to secure and maintain

The objective of this research was to determine whether Acronis’ authentication flow could be replicated programmatically using direct HTTP requests, enabling:

• cross‑platform automation (Windows, Linux, macOS)

• faster execution

• reduced operational fragility

• improved security posture

• a foundation for future tooling (reporting, auditing, onboarding, etc.)

3. Methodology

The investigation followed an empirical, failure‑mode‑driven approach:

1. Capture browser behavior
   Observed the exact sequence of HTTP requests, cookies, and JSON payloads used by the Acronis login page.

2. Reproduce the flow manually
   Used PowerShell’s Invoke-WebRequest and WebRequestSession to replicate browser behavior step‑by‑step.

3. Trigger and document failure modes
   Intentionally tested incorrect credentials, malformed JSON, unapproved networks, and invalid MFA codes.

4. Validate session behavior
   Confirmed that cookies, session binding, and MFA verification behave consistently across attempts.

5. Port the validated logic to Python
   Re‑implemented the flow using requests.Session() to confirm cross‑platform viability.

This approach ensured that the final POC was grounded in observed system behavior rather than assumptions.

4. Key Findings

4.1 Session Initialization Is Required

A GET request to https://us-cloud.acronis.com/login seeds the session with required cookies.
Skipping this step results in inconsistent or failed authentication.

4.2 Login Requires Strict JSON Structure

The login endpoint (/api/1/login) rejects malformed JSON with the error:

• “username was not specified”

This indicates that Acronis performs strict field validation and expects UTF‑8 JSON with no BOM or extraneous fields.

4.3 Password Validation Produces a Distinct Error

Incorrect credentials reliably produce:

• “invalid password”

This allows deterministic detection of credential failure.

4.4 Network Restrictions Are Enforced at Login

When logging in from an unapproved public IP, Acronis returns:

• “access from this IP address is denied”

This confirms that Access Control is enforced server‑side and can be programmatically detected without UI scraping.

4.5 MFA Verification Is a Separate Step

The MFA endpoint (/api/2/totp/verify) must be called after successful credential validation.
Invalid or expired codes produce distinct errors:

• “invalid code”

• “expired”

4.6 Authenticated Requests Fail Gracefully

Requests to authenticated endpoints (e.g., /api/1/profile) return:

• “authN flags do not match”

when the session is invalid or the IP changes mid‑session.

This provides a reliable signal for session invalidation.

5. Outcomes

5.1 Hardened PowerShell POC

A modular PowerShell script was developed that:

• initializes the session

• performs login

• handles MFA

• detects all validated failure modes

• retrieves authenticated profile data

This script is production‑ready and can be packaged into a standalone Windows executable.

5.2 Hardened Python POC

A parallel Python implementation was created using requests.Session().
It mirrors the PowerShell logic and is suitable for:

• Linux servers

• macOS systems

• containerized environments

• CI/CD pipelines

This version can be compiled into a self‑contained Unix binary.

5.3 Replacement for Selenium Automation

The new approach eliminates the need for:

• browser automation

• UI scraping

• fragile selectors

• headless browser dependencies

This significantly improves reliability and reduces operational overhead.

6. Strategic Implications

This research unlocks several new capabilities:

• automated compliance checks

• automated reporting and auditing

• customer onboarding workflows

• backup verification tooling

• alerting and monitoring integrations

• cross‑platform CLI utilities

• internal SDK‑style modules for future automation

The authentication POC serves as a foundation for a broader Acronis automation ecosystem.

7. Next Steps

• Expand the POC into a reusable internal library (PowerShell module + Python package)

• Add automated TOTP generation for hands‑free MFA

• Build a CLI wrapper for operational use

• Integrate authentication into existing internal automation pipelines

• Replace Selenium‑based scripts with API‑driven equivalents

8. Conclusion

The investigation confirmed that Acronis authentication can be replicated programmatically with full fidelity to browser behavior. The resulting PowerShell and Python POCs provide a hardened, deterministic foundation for cross‑platform automation and eliminate the fragility of UI‑based workflows.

This work demonstrates a clear path toward more reliable, secure, and scalable internal tooling around Acronis services.