How to Check Your PC for the 15+ "Weaponized" Apps That Install "Vidar" Malware (A Step-by-Step Guide).

 

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CISO Briefing: Your "Free" Software Is a Backdoor. How "Weaponized" Apps (Vidar) Bypass Your EDR. (A CISO's Hunt Guide) — by CyberDudeBivash

By CyberDudeBivash · 01 Nov 2025 · cyberdudebivash.com · Intel on cyberbivash.blogspot.com

LinkedIn: ThreatWirecryptobivash.code.blog

INFOSTEALER • EDR BYPASS • LOTL • RANSOMWARE • VIDAR

Situation: "Shadow IT" is your #1 attack vector. APTs (Advanced Persistent Threats) are *not* using 0-days. They are *Trojanizing* "free" or "cracked" legitimate software (e.g., "Photoshop Crack," "Free Video Editor") and your *employees are installing it*. This "Weaponized App" TTP is the primary vector for the Vidar Infostealer.

This is a decision-grade CISO brief. This is a "Trusted Process" Bypass. Your EDR (Endpoint Detection and Response) is *whitelisted* to trust `setup.exe` and `powershell.exe`. This fileless, "Living off the Land" (LotL) attack *exploits* that trust to steal all your corporate *session cookies* (MFA Bypass) and *AWS/GitHub keys* *before* deploying ransomware.

TL;DR — "Cracked" software from Google is the new backdoor. Your EDR is blind.

• The TTP: SEO Poisoning → User downloads `Photoshop_Crack.zip` → User runs `setup.exe` → `setup.exe` (Trusted) → `powershell.exe -e ...` (Fileless C2 Beacon).
• The "EDR Bypass": Your EDR is *whitelisted* to *trust* installers and `powershell.exe`. It *cannot* detect the *malicious intent* of this "trusted" process chain.
• The Impact (Vidar): Infostealer. It steals *everything* in 30 seconds:
  1. All saved `chrome://passwords` and `chrome://payments`.
  2. All *active session cookies* (MFA Bypass for M365, Salesforce).
  3. All `~/.aws/` and `~/.ssh/` keys (Developer/Cloud Breach).
  4. All Crypto Wallets (`wallet.dat`).
• THE ACTION (CISO): 1) HARDEN: You *must* use Application Control (WDAC/AppLocker) to *block all un-vetted executables*. 2) HUNT: This is the mandate. Hunt for anomalous `powershell.exe` child processes *now*.

TTP Factbox: "Vidar" (Weaponized App)

TTP	Component	Severity	Exploitability	Mitigation
Trojanized App (T1566)	"Cracked" / "Free" Software	Critical	User "Self-Infection"	AppLocker / MDR
Infostealer (T1555.003)	`powershell.exe` (Fileless)	Critical	EDR Bypass (LotL)	MDR (Threat Hunting)

Critical Data Breach EDR Bypass TTP MFA Bypass TTP

Contents

1. Phase 1: The "Trusted" Trojan (Why Your EDR Fails)
2. Phase 2: The "Vidar" Kill Chain (From "Free App" to Enterprise Breach)
3. Exploit Chain (Engineering)
4. Reproduction & Lab Setup (Safe)
5. Detection & Hunting Playbook (The *New* SOC Mandate)
6. Mitigation & Hardening (The CISO Mandate)
7. Audit Validation (Blue-Team / *User Guide*)
8. Tools We Recommend (Partner Links)
9. CyberDudeBivash Services & Apps
10. FAQ
11. Timeline & Credits
12. References

Phase 1: The "Trusted" Trojan (Why Your EDR Fails)

As a CISO, you've spent millions on a "Next-Gen" EDR (Endpoint Detection and Response) stack. Your vendor promised "AI-powered protection." Yet, this attack bypasses it completely. Why?

It's because this attack *never uses a "virus"*. It's a "Living off the Land" (LotL) attack that exploits your EDR's *trust*.

1. The SEO Poisoning (The "Bait")

Your Secure Email Gateway (SEG) is useless. The attack doesn't *start* with an email. It starts with your employee (or your developer) Googling a "benign" term:

• "free Adobe Photoshop download"
• "cracked video editor"
• "free productivity tool"

The Gootloader gang *poisons* Google's search results to make their *malicious website* (a fake forum) rank #1.

2. The "Self-Infection" (The "Trojan")

The user, *trusting Google*, clicks the link. The fake forum says "Click here to download your tool." It delivers a `.ZIP` file.
The user (your "trusted" employee) *willingly* double-clicks `setup.exe` and *clicks "Yes"* on the UAC (Admin) prompt.
To your EDR, this is not an "exploit." This is a "user-authorized action."

3. The "Trusted Process" (The "Bypass")

The `setup.exe` (the Trojan) executes.
Your EDR *sees* a "trusted" installer running. It *allows* it.
This installer *spawns* `powershell.exe -e ...` (a fileless, in-memory script).
Your EDR *sees* a "trusted" installer spawning another "trusted" Microsoft process. It logs this as "noise" and *allows it*.
This is the EDR Bypass. The Vidar Infostealer is now running *in-memory* inside `powershell.exe`.

Phase 2: The "Vidar" Kill Chain (From "Free App" to Enterprise Breach)

This is the full ransomware and espionage kill chain that our Incident Response (IR) teams are seeing in the wild.

Stage 1: Initial Access (The Google Search)

Your employee, `user@yourcompany.com`, clicks a poisoned Google search result for "free software."

Stage 2: Execution (The "Self-Infection")

The user opens `Photoshop_Crack.zip` and double-clicks `setup.exe`, giving it `SYSTEM` rights.

Stage 3: C2 & Collection (The "Vidar" Infostealer)

The fileless PowerShell script (the "Vidar" payload) executes *in-memory*. It does not beacon to a "known-bad" IP. It beacons to a "trusted" C2, like `api.anthropic.com` (the "PROMPTFLUX" TTP) or a "clean" IP on a "Rogue" ISP.
It *immediately* scrapes the "hostage" data:

• All `chrome://settings/passwords` and `chrome://settings/payments`.
• All *active session cookies* for M365, Salesforce, Google, etc.
• All `~/.aws/credentials`, `~/.ssh/id_rsa`, and `~/.kube/config` files.
• All `wallet.dat` (Bitcoin, etc.) files.

Stage 4: Post-Exploitation (The "MFA Bypass")

The attacker *now* has your employee's *active M365 session cookie*.
They *bypass MFA*. They *log in as your employee* from their C2 server.
Your Zero-Trust policy *allows* this, as it sees a "valid session."
The attacker is *in*. They pivot to your Domain Controller. They deploy ransomware.
The "hostage" is no longer just your employee's PC. It's your *entire enterprise*.

Exploit Chain (Engineering)

This is a "Trusted Process" Hijack (T1219/T1059). The "exploit" is a *logic* flaw in your EDR Whitelisting policy.

• Trigger: User double-clicks `setup.exe`.
• Precondition: EDR/AV is configured to *automatically trust* all `powershell.exe` processes, *especially* when spawned by an "installer".
• Sink (The RCE): `explorer.exe` → `setup.exe` (Trojan) → `powershell.exe -e ...` (Fileless Infostealer/C2)
• Module/Build: `setup.exe` (Trusted), `powershell.exe` (Trusted).
• Patch Delta: There is no "patch." The "fix" is Application Control (WDAC) and MDR (Threat Hunting).

Reproduction & Lab Setup (Safe)

You *must* test your EDR's visibility for this TTP.

• Harness/Target: A sandboxed Windows 11 VM with your standard EDR agent installed.
• Test: 1) Create a simple `.exe` that does *one* thing: `CreateProcess("powershell.exe", "-c calc.exe");`
• Execution: Double-click the `.exe` file.
• Result: Did `calc.exe` launch? Did your EDR fire a P1 (Critical) alert for `test.exe -> powershell.exe -> calc.exe`? If it was *silent*, your EDR is *blind* to this TTP.

Detection & Hunting Playbook (The *New* SOC Mandate)

Your SOC *must* hunt for this. Your SIEM/EDR is blind to the exploit itself; it can *only* see the *result*. This is your playbook.

• Hunt TTP 1 (The #1 IOC): "Anomalous Child Process." This is your P1 alert. Your `setup.exe` (or any non-admin tool) should *NEVER* spawn a shell (`powershell.exe`, `cmd.exe`).

  # EDR / SIEM Hunt Query (Pseudocode)
  SELECT * FROM process_events
  WHERE
    (parent_process_name = 'setup.exe' OR parent_process_name = 'installer.exe' OR parent_process_name = 'wscript.exe')
    AND
    (process_name = 'powershell.exe' OR process_name = 'cmd.exe')
    AND
    (command_line CONTAINS '-e' OR command_line CONTAINS '-enc')
            

• Hunt TTP 2 (The C2): "Show me all *network connections* from `powershell.exe` to a *newly-registered domain* or *anomalous IP*."
• Hunt TTP 3 (The *Result*): "Impossible Travel / Anomalous Session." Hunt your *cloud* logs. "Show me *all* admin/C-suite logins from *new, non-VPN* IPs." This is what our SessionShield app automates.

Mitigation & Hardening (The CISO Mandate)

This is a DevSecOps and Zero-Trust failure. This is the fix.

• 1. HARDEN (The *Real* Fix): This is your CISO mandate. Application Control (WDAC/AppLocker). You *must* move from a "blocklist" (what's bad) to an "allowlist" (what's *known good*). Create a GPO that *only* allows *your* known-good publishers (e.g., "Microsoft," "Google," "Cisco"). This *kills* the "Shadow IT" TTP.
• 2. HUNT (The "MDR" Fix): You *cannot* run a 9-to-5 SOC. You *must* have a 24/7 human-led MDR team (like ours) to hunt for the *behavioral* TTPs (like Hunt TTP 1) that your EDR will log but *not* alert on.
• 3. DETECT (The "Session" Fix): You *must* assume the token *will* be stolen. SessionShield is the *only* tool that *behaviorally* detects the *anomalous use* of that stolen session and *kills it*.

Audit Validation (Blue-Team / *User Guide*)

Run this *today*. This is not a "patch"; it's an *audit*.

How to Check Your PC (Consumer/User):

1. AUDIT: Go to `Settings > Apps > Installed apps`. *Audit this list*. Do you see "Free Video Editor" or any tool you *don't* recognize? **UNINSTALL IT NOW.**
2. SCAN: Run a *full, deep scan* with a *real* security suite, not just the "free" one.
   Recommended Tool: Kaspersky Premium is our #1-rated defense. It *blocks* the infostealer TTP and includes a Password Manager.
   Get Kaspersky Premium (Partner Link) →
3. HARDEN: Go to `chrome://settings/payments`. *Delete all saved cards*. Use a *Password Manager*.

How to Check Your Fleet (CISO):

# 1. Audit your EDR (The "Lab" Test)
# Run the `setup.exe -> calc.exe` test. 
# Did your EDR *see* it? If not, it is BLIND.

# 2. Audit your Logs (The "Hunt")
# Run the "Hunt TTP 1" query *now*.
# If you find `powershell.exe -e`, you are BREACHED.
  

Is Your "Shadow IT" a "Fileless" Backdoor?
Your EDR is blind. Your SOC is slow. CyberDudeBivash is the leader in Ransomware Defense. We are offering a Free 30-Minute Ransomware Readiness Assessment to show you the *exact* gaps in your "LotL" and "Data Exfil" defenses.

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Recommended by CyberDudeBivash (Partner Links)

You need a layered defense. Here's our vetted stack for this specific threat.

Kaspersky EDR
This is your *sensor*. It's the #1 tool for providing the behavioral telemetry (process chains, network data) that your *human* MDR team needs to hunt. Edureka — DevSecOps Training
This is a *developer* failure. Train your devs *now* on Application Control (WDAC) and Secure Coding. Alibaba Cloud (VDI)
A key mitigation. Use Virtual Desktop Infrastructure (VDI). If the VDI is popped, you *burn it* and re-image in seconds. The host is safe.

AliExpress (Hardware Keys)
*Mandate* this for all Domain Admins. Get FIDO2/YubiKey-compatible keys. They stop the *initial phish* from succeeding. TurboVPN
Your developers are remote. You *must* secure their connection to your internal network. Rewardful
Run a bug bounty program. Pay white-hats to find flaws *before* APTs do.

CyberDudeBivash Services & Apps

We don't just report on these threats. We hunt them. We are the "human-in-the-loop" that your automated EDR is missing.

• Managed Detection & Response (MDR): This is the *solution*. Our 24/7 SOC team becomes your Threat Hunters, watching your EDR logs for these *exact* "LotL" TTPs.
• Adversary Simulation (Red Team): This is the *proof*. We will *simulate* this exact "Fileless" kill chain to show you where you are blind.
• Emergency Incident Response (IR): You found this TTP? Call us. Our 24/7 team will hunt the attacker and eradicate them.
• PhishRadar AI — Stops the phishing attacks that *initiate* the breach.
• SessionShield — Protects your *admin sessions* from the *credential theft* that happens after this breach.

Book Your FREE 30-Min Assessment Explore 24/7 MDR Services Subscribe to ThreatWire

FAQ

Q: What is "Vidar"?
A: Vidar is a potent Infostealer malware. Its *only* goal is to steal data from your PC, specifically *credentials*. It targets saved browser passwords, session cookies, cryptocurrency wallets, and developer credentials (AWS/SSH keys).

Q: Why does my EDR/Antivirus miss this attack?
A: Because your EDR is *configured to trust* `powershell.exe` and `wscript.exe`. This is a "Trusted Process" bypass. The EDR sees a 'trusted' Microsoft process running and *ignores* it. You *must* have a *human* MDR team hunting for the *behavioral* anomalies.

Q: What is "Shadow IT"?
A: It's the use of *any* software, hardware, or cloud service by employees *without* the explicit knowledge and security oversight of the IT/Security department. It is the #1 vector for "Trusted Process" bypasses.

Q: What's the #1 action to take *today*?
A: HARDEN. Go to your Group Policy (GPO) and *change the default file handler* for `.JS` and `.VBS` files from `wscript.exe` (Execute) to `notepad.exe` (View). This *de-weaponizes* the TTP instantly. Your *second* action is to call our team to run an emergency Threat Hunt for this TTP.

Timeline & Credits

This "Weaponized App / LotL" TTP (T1566/T1059) is an active, ongoing campaign by multiple APTs and RaaS groups like Gootloader and the groups that deploy Vidar/Redline.
Credit: This analysis is based on active Incident Response engagements by the CyberDudeBivash threat hunting team.

References

• MITRE ATT&CK: T1555.003 (Credentials from Web Browsers)
• MITRE ATT&CK: T1059.001 (PowerShell)
• MITRE ATT&CK: Vidar Infostealer
• CyberDudeBivash MDR Service

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#Vidar #Infostealer #EDRBypass #FilelessMalware #LotL #CyberDudeBivash #IncidentResponse #MDR #ThreatHunting #CISO #Ransomware #SessionHijacking