ERMAC v3.0 Banking Malware — Source Code Exposed via Weak Password “changemeplease” By CyberDudeBivash — your daily dose of ruthless, engineering-grade threat intel

August 16, 2025

ERMAC v3.0 Banking Malware — Source Code Exposed via Weak Password “changemeplease” By CyberDudeBivash — your daily dose of ruthless, engineering-grade threat intel

Executive summary

Researchers obtained the full ERMAC v3.0 Android banking trojan source code after finding an exposed archive in an open directory. The leak reveals a complete MaaS (malware-as-a-service) stack—PHP/Laravel C2 backend, React operator panel, a Golang exfil server, Docker files, and the Android builder—plus embarrassing hard-coded secrets, including root credentials with the password changemeplease, a hard-coded JWT secret, and tenant-wide bearer tokens. The campaign targets 700+ banking/crypto/shopping apps using overlay (“inject”) pages and AES-CBC communications. The exposure gives defenders concrete pivots (cookies, routes, build artifacts, and IPs) to track and disrupt active infrastructure. The Hacker NewsHunt

What happened (timeline & discovery)

Mar 6, 2024 — An open directory on 141.164.62[.]236:443 hosted Ermac 3.0.zip with the full codebase (backend, frontend, golang, docker, builder). Hunt
Aug 14–16, 2025 — Public write-ups detail the leak and its weaknesses; outlets summarize key takeaways for defenders. HuntThe Hacker News

What leaked (and why it matters)

Complete stack & routes. The backend exposes rich operator APIs (e.g., .../injects/*, .../sendBotsCommand, .../accounts/*) and uses the session cookie ermac_session—a direct pivot to find live panels by signature hunting. Hunt

Hard-coded secrets & weak defaults. Analysis highlights:

A hard-coded JWT secret and static admin bearer token.
Default root creds with password changemeplease.
Open account registration on the admin panel.
All three enable trivial panel takeover and telemetry collection against active crews. HuntCyber Security News

Capabilities uplift in v3.0. Compared with earlier ERMAC/Hook strains, v3.0 expands overlay injects to 700+ apps, adds an improved panel, a new Android backdoor (Kotlin), and AES-CBC comms. The Hacker News

Lineage context. ERMAC descends from the Cerberus codebase; later branches overlap with Hook variants—useful for clustering families and re-using detections. The Hacker Newsnccgroup.com

How ERMAC v3.0 attacks work (operator view)

Provision: Spin up the leaked backend + panel + exfil server (Go) from Docker or scripts. Hunt
Build: Use the builder to generate an APK with campaign config (app name, C2 URL, keys). The Hacker News
Delivery: Side-load, fake updates, SEO/malvertising, or smishing to install the APK.
Steal: Abuse Accessibility and overlays to present look-alike login screens for 700+ apps, exfiltrate entered creds/SMS/2FA. The Hacker News
Operate: Panel commands for device control, SMS grabbing, call forwarding, file ops; data funnels to the Go exfil server over AES-CBC. The Hacker News

Why this leak is a defender’s gift

Attribution & takedown: The leak’s routes, cookies, and code strings (e.g., ermac_session) are search beacons for mapping live C2s/panels. Hunt
Credential re-use: changemeplease and other defaults historically reappear across actor infra—test them (legally) during coordinated takedowns. HuntCyber Security News
Hunting shortcuts: Outlets published host/network observables (IPs, hashes) and note that Hunt.io shared YARA / SQL pivots to seed hunts. Cyber Security News

Indicators & pivots (selected)

Use these as seeds; verify in your intel pipeline.

Cookie signature: ermac_session in HTTP responses → likely ERMAC panel. Hunt
Archive/hash (source): Ermac 3.0.zip — SHA-256 175d4a...992aaa. Go exfil binary SHA-256 8c81ce...e8d545. Hunt
Example infra from reporting: Panels/C2/exfil servers observed across multiple ASNs; reporting includes entries like 43.160.253[.]145:80/8089, 91.92.46[.]12:80, and the open directory host 141.164.62[.]236. (Validate freshness before blocking.) Cyber Security News

Detection engineering (practical, copy-paste ready)

1) Internet-wide & perimeter hunts

HTTP signature search: Look for Set-Cookie: ermac_session or panel routes (/api/v1/injects/*, /api/v1/sendBotsCommand). (Edge IDS/WAF logs, passive HTTP sensors.) Hunt
TLS/HTTP fingerprints: Cluster by common panel assets and route names from the leak to enumerate sibling hosts. Hunt

2) Android fleet (MDM/EDR/Play console)

Alert on unknown APKs with Accessibility + SYSTEM_ALERT_WINDOW + RECEIVE_SMS/READ_SMS permission triad—classic overlay banker profile.
Hunt for dynamic overlay usage against finance/crypto app package names (from the leaked inject list). The Hacker News
Network egress from managed devices to the IPs/ports above; inspect for AES-CBC beacons matching campaign cadence. The Hacker NewsCyber Security News

3) Fraud/SOC correlation

Tie new device logins and SIM-swap reports with recent APK installs or SMS-forwarding anomalies; bankers frequently stage BEC-style drain after overlay capture.

Mitigation & hardening (priority-ordered)

A. For enterprises (BYOD/COPE Android)

Block sideloading in MDM; enforce Google Play/Play Integrity API.
Enforce per-app VPN and DNS sinkhole for finance apps; block connections to known ERMAC infra. Cyber Security News
Require latest Play Protect and Android security patch levels; quarantine devices requesting Accessibility for non-assistive reasons.
Add overlay protection to critical internal apps (detect obscured windows, FLAG_SECURE, challenge on focus change).

B. For banks/fintech app teams

Overlay hardening: Enforce Secure Flag, detect tapjacking, verify in-app focus, and server-side strong device fingerprinting before authorizing high-risk actions.
Out-of-band MFA (push with number/phrase match), per-transaction risk controls, and session-binding to device attestation.
Threat intel ingestion: Track ERMAC inject package targets; test against your app builds. The Hacker News

C. For telcos & payment partners

Prioritize SIM-swap monitoring, rapid number-porting holds, and SMS-interception risk models for flagged accounts.

Incident response playbook (ERMAC suspected)

Hour 0–2 — Contain

Block observed ERMAC endpoints in DNS/Firewall/CDN; revoke sessions of impacted users; force in-app re-auth with device attestation.
For managed devices: isolate and collect APK + logs.

Hour 2–12 — Scope

Pivot from victim reports to overlay telemetry (crash logs, accessibility service usage), then cross-check with bank fraud events.
Enumerate infra by hunting ermac_session and leaked routes across perimeter telemetry; share hits with your ISP/CSIRT. Hunt

Hour 12–48 — Eradicate & harden

Purge APKs estate-wide via MDM; rotate credentials for affected users; enable transaction step-up.
Add temporary geo/velocity blocks and lower auth trust for impacted cohorts.

MITRE ATT&CK® mapping (mobile & enterprise)

Initial access: Malicious/repurposed app (T1475), SMS phishing (T1454)
Credential access: Overlay capture & keylogging (T1417), SMS/2FA theft (T1411)
Collection/Exfil: Exfil via C2 channel (T1409) with AES-CBC comms The Hacker News
Defense evasion: Accessibility abuse (T1542), packer/obfuscation, panel-side operator controls
Impact: Fraudulent transactions, account takeover

Key takeaways for the board

Exposure created defender leverage. Hard-coded secrets (changemeplease, JWT/bearer) and stable routes/cookies are reliable pivots to find and disable live infra. HuntCyber Security News
Mobile fraud is supply-chain-like. ERMAC’s builder + panel commoditize campaigns; treat it like SaaS for crime and block at platform edges. The Hacker News
Speed matters. Convert today’s IOCs into preventive controls (MDM, WAF/CDN, DNS, app attestation) before actors rotate infra.

Sources & further reading

Hunt.io — ERMAC V3.0: Full Source Code Leak & Infrastructure Analysis (Aug 14, 2025). Details on open directory, stack, routes, and changemeplease default. Hunt
The Hacker News — ERMAC V3.0 Banking Trojan Source Code Leak Exposes Full Malware Infrastructure (Aug 16, 2025). High-level summary and capability uplift. The Hacker News
CyberSecurityNews — ERMAC v3.0 Source Code Exposed via Weak Password ‘changemeplease’ (Aug 16, 2025). Mentions weak root password and published observables. Cyber Security News
NCC Group — From ERMAC to Hook (Sept 11, 2023). Family lineage & overlap context. nccgroup.com

Author: CyberDudeBivash
Powered by: CyberDudeBivash
Links: cyberdudebivash.com | cyberbivash.blogspot.com
Hashtags: #CyberDudeBivash #ERMAC #AndroidMalware #BankingTrojan #OverlayAttacks #MobileSecurity #ThreatIntel #MaaS #DFIR #AppSec

Search This Blog

Cyberdudebivash