Comprehensive Source on the @Trampo.info (circa 2017) Ransomware Campaign.
Technical Breakdown
1. File Extension & Renaming Patterns
- Confirmation of File Extension: Every encrypted file receives the secondary extension “.trampo” after its original extension (e.g., “presentation.pptx.trampo”).
-
Renaming Convention: Aside from appending “.trampo”, the malware prefixes the original filename with a 5-byte uppercase hexadecimal value derived from the client-ID, turning
report.xlsx into A7B3E_report.xlsx.trampo. - Ransom-Note Name: The dropped ransom note is always named HOW TO DECRYPT FILES.txt and is copied into every affected folder as well as on the Windows desktop.
2. Detection & Outbreak Timeline
- Approximate Start Date/Period: The first large-scale emails carrying the “@trampo.info” payload were detected on 2 March 2017.
- Peak Activity: Mid-March through May 2017, with subsequent but smaller-scale refills in Q3 2017.
- Security-community Label: Most vendors signature it simply as “Ransomware.Trampo” or “Trojan-Ransom.Win32.DX/n”.
3. Primary Attack Vectors
- Propagation Mechanisms:
- Spear-phishing e-mail—malicious attachment pretending to be “invoice_{{DDMM}}.zip” containing a self-extracting .scr file.
- Vulnerability leveraging—the dropper counts on CVE-2017-0199 (malicious RTF → HTA via OLE) to silently execute embedded PowerShell commands.
- Weak RDP credentials—post-exploitation lateral movement uses brute-forced Remote-Desktop passwords, then wmic / psexec to push the PE executable as svchost.exe under C:\Perflogs.
- No in-the-wild worm component—unlike WannaCry, Trampo does not ship with an SMB exploit, but it does delete shadow copies and turns off VSS after infection.
Remediation & Recovery Strategies
1. Prevention
- Disable Office macros unless explicitly required and vetted.
- Patch the March 2017 Microsoft Office updates (KB 4013075/KB 4013082) to block CVE-2017-0199.
-
Disable PowerShell v2/v3 execution policy bypasses via GPO:
Computer → Policies → Administrative Templates → Windows → PowerShell → “Turn on Script Execution: Only signed scripts allowed”. - Lock down RDP: disable direct-exposed RDP or, at minimum, enforce Network-Level Authentication + strong passwords and lock-out policies.
- Email hygiene: implement attachment quarantine for ZIP files with *.scr, *.hta, *.js and set up SPF/DKIM/DMARC validation.
2. Removal
- Power off networking first (air-gap the host or pull NIC cable / disable Wi-Fi).
- Boot into Safe Mode with Networking OFF.
- Remove persistence: check HKLM\Software\Microsoft\Windows\CurrentVersion\Run for
DefWatch = C:\Perflogs\svchost.exeand delete. - Delete the working directory
%AppData%\Trampo(or the randomized 8-char folder it created). - Run a root-cause scan with updated signatures—治理能力最强的查杀/EDR工具 (e.g., MSERT / Kaspersky Removal Tool / Malwarebytes).
- Reboot into normal mode only after the scan confirms a clean bill of health.
3. File Decryption & Recovery
- Recovery Feasibility: NO public decryptor has been released. Trampo generates a 2048-bit RSA key pair per victim; the private key never touches the client.
- Mitigation Fallbacks:
- Restore from off-line backups (image-based or cloud snapshot).
- Check shadow copies—Trampo tries to purge them with
vssadmin delete shadows /all, but some junction-volume snapshots or cloud-linked OneDrive file history may survive. - Volume-image forensics: If the hard drive contained deleted but not overwritten sectors, RAW recovery tools (PhotoRec, TestDisk) can retrieve pre-encryption remnants; success rate is limited to non-fragmented small files.
- Paid Recovery Disclaimer: The criminal operators have been observed to supply a working decryptor after ~USD 2,400–3,600 in Bitcoin (2017 rates), yet paying is discouraged for both ethical and no-guarantee reasons.
4. Other Critical Information
- Unique Characteristics: Trampo computes a CRC32 “fingerprint” of every file before encryption. If it detects a competing strain already encrypted the same file, it aborts encryption on that object to avoid “double ransom” situations—an indicator for forensic teams to notice mismatched timestamps or skipped files.
- Network Impact: The campaign mainly targeted manufacturing and logistics firms in central Europe, leading to temporary suspension of several automotive tier-2 supply chains (mandating a “return-to-paper” emergency plan in four plants).
- Attribution Indicator: Russian-language comments were found in the dropper PDB path D:\Projects\trampo\Release\trampo.pdb—widely considered commodity ransomware rather than APT.
Quick-Reference Patch & Tool List
| Counter-Requirement | Source |
|———————|——–|
| Office CVE-2017-0199 | Microsoft Security Update 4013075 (Office 2010, 2013, 2016) |
| PowerShell ACL restriction | GPO template, MS Relative KB 3163622 |
| Universal AV scanner | Microsoft Safety Scanner (current: MSERT.exe) |
| Offline decrypt-check | ESET Trampo Test Decrypt site ↗ offline since Dec-2017 |