Infostealer economics: why DarkCloud is becoming a preferred threat for financially motivated attackers

Ransomware still grabs headlines, but the underground economy has been quietly rewarding a different business model: cheap, scalable credential theft. Feature-rich infostealers such as DarkCloud are pushing the risk–reward balance towards “log stealing” rather than towards loud, disruptive encryption.

DarkCloud is a useful case study because it combines three things attackers love: broad data collection, flexible exfiltration, and a low barrier to entry (including a builder-style ecosystem). Recent threat reporting also shows it’s being delivered via finance-themed spear-phishing, with ongoing development focused on evasion and modularity.

The economic shift: why credentials beat encryption (more often than you think)

Ransomware is a high-yield crime, but it’s also high-friction:

• You need dependable access and privileges.
• You need time on target to spread, disable controls, and stage data.
• You create an “incident that can’t be ignored”, which triggers containment, law enforcement involvement, insurance scrutiny, and (increasingly) refusal to pay.

Infostealers flip that equation. They monetise quickly, often within hours, and they do it quietly.

Flashpoint-linked reporting highlights just how large the credential economy has become: infostealers were used to steal billions of credentials in 2024, and infected tens of millions of hosts. (cyberscoop.com) That scale matters because it creates a liquid marketplace: steal once, sell many times, and let other criminals take the operational risk.

DarkCloud’s appeal: a “commodity” stealer with enterprise-grade outcomes

DarkCloud is commonly described as an infostealer, but its feature set is designed for repeatable profit.

Recent technical summaries show DarkCloud collecting credentials, cookies, and payment data, scraping email contacts (useful for follow-on phishing), and staging data locally before exfiltration. (flashpoint.io) In other write-ups, DarkCloud is also associated with crypto wallet targeting and multiple operator-friendly exfiltration choices (e.g., Telegram and FTP). (advisory.eventussecurity.com)

Just as importantly, DarkCloud’s ongoing evolution includes anti-analysis and sandbox checks, plus obfuscation approaches intended to slow reverse engineering and detection engineering. (advisory.eventussecurity.com)

Why this changes the attacker’s incentive structure

For financially motivated actors, DarkCloud-like stealers enable a portfolio approach:

1. Harvest credentials and session artefacts at scale
2. Monetise immediately (sell logs, sell access, drain wallets, commit payment fraud)
3. Optionally escalate later (business email compromise, cloud takeover, or even ransomware)

In other words, infostealers don’t replace ransomware—they increasingly feed it. SpyCloud’s research has also framed infostealer-driven identity exposure as a major enabler for downstream attacks, including ransomware. (globenewswire.com)

Risk–reward comparison: ransomware vs infostealer operations

What defenders should take away: identity is the new battleground

Infostealers turn endpoints into identity-extraction points: browser credentials, session cookies, and tokens become the prize. That has two immediate implications:

1. Your identity telemetry is now a primary detection surface, not just an audit trail.
2. Token replay and “valid account” abuse become expected, not exceptional.

Microsoft’s own guidance on token theft emphasises monitoring for suspicious token usage and pairing that monitoring with Conditional Access and Identity Protection signals. (learn.microsoft.com)

Proactive monitoring priorities for DarkCloud-style threats

Detection can’t rely on one signal. You need coverage across email, endpoint, identity, and data movement.

Email and initial access: stop the “cheap entry” stage

DarkCloud campaigns have been observed using spear-phishing themes designed to trigger urgency in finance and procurement workflows. (ics-cert.kaspersky.com)

Focus on:

• Blocking risky attachment types and container formats (ZIP chains, embedded executables)
• Detecting “business workflow abuse” (helpdesk ticketing channels, shared mailboxes)
• Auto-quarantining based on detonation + behaviour, not just signatures

Endpoint behaviour: look for stealing and staging, not just malware names

DarkCloud reporting notes local staging behaviour (structured directories under user profile paths) before exfiltration. (flashpoint.io)

Prioritise detections for:

• Unusual access to browser credential stores and cookie databases
• Suspicious process trees (email client / archive tool → script host → new binary)
• Clipboard scraping and wallet-directory access (high-signal for financially motivated ops)

Identity and cloud: hunt for token replay and “valid account” patterns

When infostealers capture cookies and refresh tokens, traditional password resets may not be enough on their own.

Microsoft Entra ID Protection includes risk detections such as anomalous token (sign-in) and other signals designed to highlight suspicious token properties and potential replay. (learn.microsoft.com)

Practical monitoring moves:

• Alert on risky sign-ins and unfamiliar sign-in properties (especially non-interactive sign-ins)
• Correlate “new device + new location + new application” sign-ins with endpoint alerts
• Enforce reauthentication for sensitive operations where possible (reduce session value to attackers) (learn.microsoft.com)

Exfiltration: detect the “log shipping” channels

DarkCloud supports multiple exfiltration methods (including SMTP, FTP, Telegram, and HTTP), giving attackers flexibility when one path is blocked. (flashpoint.io)

Monitoring ideas:

• Unusual outbound SMTP from endpoints that shouldn’t send mail directly
• FTP connections from user workstations
• Suspicious traffic patterns to messaging APIs and newly seen infrastructure

Why this is a Microsoft Sentinel problem (and how to make it manageable)

Microsoft Sentinel is well positioned for this threat class because infostealer outcomes show up as cross-domain signals: endpoint alerts, identity risk, mail events, firewall/proxy logs, and (later) privilege activity.

The challenge is speed and consistency—especially when your SOC is stretched.

That’s where SecQube is designed to help.

How SecQube helps teams operationalise infostealer defence in Sentinel

Infostealer defence is a workflow problem as much as a tooling problem: triage, confirm, contain, and stop re-use of identity artefacts before they become a wider breach.

SecQube’s AI-powered, multi-tenant platform for Microsoft Sentinel is built to reduce the effort of that workflow:

• Harvey provides conversational, analyst-friendly investigation support and generates incident-specific triage steps to keep work consistent across analysts and shifts. (secqube.com)
• Investigate supports no-code KQL generation so teams can pivot faster from “suspicious sign-in” to “what happened on the device?” without requiring deep KQL expertise. (secqube.com)
• Built-in ticketing and notifications keep identity + endpoint evidence tied to an auditable case record, without scattering context across tools. (secqube.com)
• Change management helps ensure containment steps (token revocation, Conditional Access adjustments, mailbox rules cleanup) are tracked and approved cleanly. (secqube.com)

If you’re running an MSSP or multi-tenant SOC, SecQube’s Azure Lighthouse-aligned approach is designed specifically for managing multiple Sentinel workspaces with consistent processes. (secqube.com)

What “good” looks like in 2026: reduce the value of stolen identity

DarkCloud is popular for the same reason many stealers succeed: it turns a single click into reusable access and immediate financial upside.

To shift the economics back in your favour:

• Make credential theft harder (email + endpoint hardening)
• Make stolen sessions less reusable (token and session controls, risk-based access)
• Make detection faster (identity risk + endpoint behaviour correlation)
• Make response repeatable (clear triage steps, automated workflows, auditable tickets)

Infostealers thrive when defenders treat identity compromise as a secondary effect. In reality, it’s the primary objective—and the earliest moment you can still win the fight.

If you want to see how SecQube streamlines infostealer triage inside Microsoft Sentinel using Harvey and Investigate, explore the SecQube platform and features. (secqube.com)