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Posted on • Originally published at threatchain.io

AgentTesla Sample Detected: Nota de credito A12345-045_20260403_pdf.scr.exe

#security #malware #cybersecurity #agenttesla

This article was originally published on ThreatChain — decentralized threat intelligence.

That email attachment your coworker just opened? It's copying every password they've ever saved. Right now.

A new AgentTesla sample was identified by threat intelligence feeds on 2026-04-30 18:37:46. This post breaks down what we know about the specific sample, how to recognize related activity on your network, and what to do if you or your organization might be affected.

The Sample at a Glance

Field Value
SHA-256 4a2b467d823861199497178aa9c39088b91bcb3fcb3c164238ffa039fdc0a1a0
File name Nota de credito A12345-045_20260403_pdf.scr.exe
File type exe
Size 1.04 MB
Origin (first observed) US
First seen 2026-04-30 18:37:46
Family AgentTesla
Tags AgentTesla, exe
VirusTotal detection 31/75 engines flagged malicious

What AgentTesla Does

Agent Tesla is a .NET-based keylogger and credential stealer that's been active for years. It's typically delivered via phishing and steals browser passwords, FTP credentials, and email client data.

Seeing this family on your network — or finding a file matching this hash — is a red flag. AgentTesla samples are typically distributed through phishing emails, malvertising, fake software downloads, or cracked installers. Once executed, the malware usually establishes persistence on the host, harvests credentials and sensitive data, and establishes an outbound channel to command-and-control infrastructure operated by the attackers.

Detection Landscape

Multiple security vendors have weighed in on this specific sample:

  • ANY.RUN: [{'malware_family': 'agenttesla', 'verdict': 'Malicious activity', 'file_name': '_4a2b467d823861199497178aa9c39088b91bcb3fcb3c164238ffa039fdc0a1a0.exe', 'date': '2026-04-30 18:39:27', 'analysis_url': 'https://app.any.run/tasks/abe6eaad-adfa-496c-bd33-25bb69be1ed0', 'tags': ['auto-startup', 'susp-lnk', 'evasion', 'stealer', 'ultravnc', 'rmm-tool', 'agenttesla']}]
  • CERT-PL_MWDB: agenttesla
  • vxCube: malware2
  • Intezer: suspicious
  • CAPE: AgentTesla
  • Triage: agenttesla
  • Spamhaus_HBL: [{'detection': 'suspicious', 'link': 'https://www.spamhaus.org/hbl/'}]
  • UnpacMe: [{'sha256_hash': '4a2b467d823861199497178aa9c39088b91bcb3fcb3c164238ffa039fdc0a1a0', 'md5_hash': 'acc03c3314c77136e405d9ba2b265c0c', 'sha1_hash': '25d2a0a828a22dbc0810cf9affe67ee4bab53da6', 'detections': [], 'link': 'https://www.unpac.me/results/f8f737ea-72a1-4e13-b140-4597799f7376/'}, {'sha256_hash': '882461e4ab8caffe315445bf4c7211ac1c64309b436c3e9a73185185112ebd1c', 'md5_hash': 'b82edda66e6dc485844358d3e88df9a4', 'sha1_hash': '0b8ebf2cdbbfaf37ddda0f2bc540fefe83bd6d14', 'detections': [], 'link': 'https://www.unpac.me/results/f8f737ea-72a1-4e13-b140-4597799f7376/'}, {'sha256_hash': '812ff46e29476def51ad85f7ab0f7dd0ba46d978fa30850a938f001e55850958', 'md5_hash': 'a85fb84803ad83b6e55eee50fb3eea5d', 'sha1_hash': '961de5b09c924547e7e4a2484d070bee82de6645', 'detections': ['win_agent_tesla_g2', 'AgentTesla', 'Agenttesla_type2', 'INDICATOR_EXE_Packed_GEN01', 'INDICATOR_SUSPICIOUS_EXE_SandboxHookingDLL', 'INDICATOR_SUSPICIOUS_Binary_References_Browsers', 'INDICATOR_SUSPICIOUS_EXE_References_Confidential_Data_Store', 'INDICATOR_SUSPICIOUS_EXE_References_Messaging_Clients', 'INDICATOR_SUSPICIOUS_EXE_Referenfces_File_Transfer_Clients', 'INDICATOR_SUSPICIOUS_EXE_VaultSchemaGUID'], 'link': 'https://www.unpac.me/results/f8f737ea-72a1-4e13-b140-4597799f7376/'}, {'sha256_hash': '38cb5155138ef2fd9059e7af8b0251ba27b0547db0b2848e790ccac43a47b954', 'md5_hash': 'f639e1417573d90f44e5f31dcddf2eec', 'sha1_hash': 'ab748110e582676ce1215b135442f89b71b1cb30', 'detections': ['SUSP_OBF_NET_ConfuserEx_Name_Pattern_Jan24'], 'link': 'https://www.unpac.me/results/f8f737ea-72a1-4e13-b140-4597799f7376/'}]
  • FileScan-IO: LIKELY_MALICIOUS
  • Kaspersky: Malware

Indicators of Compromise

If you're hunting for this sample or related AgentTesla activity, here are the concrete indicators to feed into your SIEM, EDR, or host-based searches:

  • SHA-256 hash: 4a2b467d823861199497178aa9c39088b91bcb3fcb3c164238ffa039fdc0a1a0
  • Filename pattern: Nota de credito A12345-045_20260403_pdf.scr.exe
  • File type: exe
  • Behavioral tags: AgentTesla, exe
  • YARA rules matched: NET, NETexecutableMicrosoft, pe_imphash, Skystars_Malware_Imphash

How to Check If You're Affected

  1. Search your endpoint logs for the SHA-256 4a2b467d823861199497178aa9c39088b91bcb3fcb3c164238ffa039fdc0a1a0. Most EDR platforms support historical hash searches across all monitored hosts.
  2. Check for the filename Nota de credito A12345-045_20260403_pdf.scr.exe in recently downloaded files, email attachments, and installer bundles.
  3. Look for outbound connections to uncommon TLDs or newly registered domains — AgentTesla typically beacons to command-and-control infrastructure shortly after execution.
  4. Review scheduled tasks and registry run keys — this family commonly establishes persistence through standard Windows autorun locations.
  5. Run an updated AV or EDR scan across potentially affected hosts. Because this sample is already in public threat intel feeds, current signatures should flag it.

What to Do If You Find It

If you find evidence of this sample or related activity on your systems:

  1. Isolate the affected host from the network immediately to prevent lateral movement.
  2. Capture memory and disk images before rebooting. Reboots destroy critical forensic evidence, especially in RAM.
  3. Rotate credentials that may have been exposed — browser-saved passwords, VPN credentials, SSH keys, and any service accounts used on the affected host. AgentTesla frequently targets these.
  4. Check for secondary payloads. AgentTesla is often a stepping stone for additional malware including ransomware or banking trojans.
  5. Report the incident to your security team. For larger organizations, consider notifying your regional CERT.

Free Threat Lookups

You can verify any suspicious hash against the ThreatChain database for free — no signup, no API key required. Paste any MD5, SHA-1, or SHA-256 at threatchain.io/lookup and get results across multiple intel sources in seconds.

For cross-referencing this specific sample, you can also look it up directly on MalwareBazaar where the original submission and vendor analysis is recorded.

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