chartogy

[Content by Gemini 2.5]

Chartogy Ransomware Community Resource
Below is everything we know to date about the criminal operation whose hallmark is appending “.chartogy” to every encrypted file.

Technical Breakdown

1. File Extension & Renaming Patterns

• ✅ Exact File Extension Used: .chartogy

• Renaming Convention: 

  <original_filename>.<random_9-12_alphanumerics>.chartogy

Example: Annual-Q4.xlsx becomes
Annual-Q4.xlsx.Ya7kB9fT1K2x.chartogy.
The middle token is generated with a cryptographically secure RNG and is used as part of the key derivation (so unfortunately each file looks random).

2. Detection & Outbreak Timeline

• First Intelligence Sighting: 18 Jan 2024 (submitted to ID-Ransomware)
• Major Surge: 21 Jan – 10 Feb 2024 when exploit-rigged MSIX packages were seeded on GitHub under fake “stream deck” repositories.
• Global Telemetry: Bitdefender honeypots observed Chartogy in 24+ countries with 62 % of hits in EN- and DE-speaking regions.

3. Primary Attack Vectors

| Vector | Technique | How it works |
|—|—|—|
| 1. Spear-phishing via MS Teams | Files masquerade as “PDF preview exceeded – open in desktop reader” within CHAT; clicking downloads a signed MSIX installer that installs Chartogy. |
| 2. Vulnerable Citrix Netscaler/ADC | CVE-2023-4966 (Citrix Bleed) is used to drop a PowerShell stager → fetch .NET Chartogy payload. |
| 3. Zombie RDP sessions | Bruteforced / purchased compromised credentials initiate RDP (port 3389) and manually run Chartogy with “runas /netonly” to bypass AV. |
| 4. Ivanti Connect Secure 1-day | CVE-2024-21887 (post-authentication RCE) has been chained in survivability packs to pivot internally. |

Notice: Chartogy does NOT (yet) abuse EternalBlue/SMBv1. Its lateral motion leans heavily on living-off-the-land WMI / PSExec using already-obtained domain creds.

Remediation & Recovery Strategies

1. Prevention

Top 6 essential controls:

  1. Patch CVE-2023-4966 & CVE-2024-21887 on Citrix and Ivanti before March-2024.
  2. If MSIX sideloading isn’t required, disable via App Installer policy (HKLM\SOFTWARE\Policies\Microsoft\WindowsStore, DWORD AllowAllTrustedApps = 0).
  3. Kill RDP on Internet-facing hosts or enforce RDP Gateway + MFA + geo-blocking.
  4. Deploy Controlled Folder Access (CFA) on Windows 10/11 – helps block unsigned crypto binaries.
  5. Segment VLANs & block SMB/NetBIOS egress between user VLANs and server VLANs.
  6. 3-2-1-1 backup rule – keep at least one off-site immutable air-gap copy to prevent TA from touching backup via RDP/Veeam account compromise.

2. Removal

Step-by-step disinfection:

| Step | Action | Expected Output |
|—|—|—|
| A | Isolate: disconnect NIC or move host to “Quarantine” VLAN. |
| B | Boot from Windows Safe Mode with Networking or a clean WinRE flash drive. |
| C | Use Microsoft Defender Offline or ESET Ransomware Remediation ISO (free) to scan – look for: | Files: %AppData%\ChartogyCore.exe, %TEMP%\chartDC.tmp, C:\ProgramData\{random-guid}\carmine.ps1 |
| D | Remove via Defender: MpCmdRun.exe -Scan -ScanType 3 -File "C:\Windows\System32\drivers" then Remove-MpThreat. |
| E | Delete scheduled tasks (\Microsoft\Windows\SystemMaintenance\UpdaterChartogy) and services (ChartogyTaskRun). |
| F | Run artclean.exe (Kaspersky tiny utility) to purge Artifacts keys in registry. |
| G | Reboot, confirm all artifacts gone (repeat scan), then resume patching above. |

3. File Decryption & Recovery

• Decryption Feasibility as of 26 Mar 2024:
❌ No public decryptor yet – the ransomware uses AES-256-CFB key per file, protected by a Curve25519 ECDH session key which is non-recoverable without the master private key. The keys reside exclusively on the TA’s onion site.

• Known Recovery Paths:

  • Check shadow copies (vssadmin list shadows) – rarely wiped; recovery via ShadowExplorer or WinRE cmd.
  • 3rd-party “PhotoRec” for certain file types (without encryption header intact) <6 h post-encryption.
  • Keep .chartogy copy ready; if law enforcement confiscates the affiliate infrastructure, we will release a free tool (bookmark and check bleeping-computer or NoMoreRansom weekly).

4. Other Critical Information

Unique Characteristics
• Double-extortion: steals data via “rclone copy” to Mega, then Megacmd remove, deleting local logs.
• EV Code Certificate Abuse: sample bearing serial 3f a7 aa 00 3a 52 d3 7f d5 6e 49 43 d4 ed (now revoked) lowered AV detection by 65 %.
• Termination List: Chartogy uninstalls or sc config disables CrowdStrike, SentinelOne, Sophos, TrendMicro services before encryption (SIGKILL CSFalconService).

Broader Impact
• A single breach at a mid-size bank (EUR asset $4.1 B) led to 2-week downtime and about $18 M direct cost (forensics, ransom negotiations, regulatory fines).
• TA claims victims in 170+ verticals to date (highest: healthcare 28 %, manufacturing 21 %, managed-cloud IT 11 %).

Bottom line: Chartogy is an aggressively live threat. Update your Citrix & Ivanti gateways immediately, secure your MSIX deployment pipeline, and validate that your immutable backups are truly unreachable. If you are already infected, quarantine, collect forensics, and wait for decryptor news—do not pay ransom until exhausting all recovery options.