File verdict·Decided by the MT AI Engine
Our call

Suspicious

PyInstaller executable with low-trust heuristic detections and offensive MITRE techniques, but no tier-1 consensus, malicious sandbox verdict, or confirmed C2 contact.

Trust score52Caution
MT AI confidence · 62%
NepTunnel 2.2.exe
19.1 MB
41b01a63bcb94d346640bc9f2402
Antivirus engines
3 of 75 flagged
Code signing
Unsigned
Age
First seen 1mo ago
MT AI Engine · our arbiter

The verdict, reasoned out.

Not a rules engine. The MT AI Engine reads every signal we collected, weighs them against history, and commits to an answer.

62%Confidence
Moderate
Reasoning

The file exhibits a mixed-signal profile. On one hand, three low-trust engines flagged it, and heuristics detected process-injection (T1055) and credential-dumper (LSASS) techniques — offensive MITRE patterns. On the other hand, all 16 tier-1 engines remained silent, no malicious sandbox verdict was issued, and 10 dropped children were inspected with zero malicious verdicts. The PyInstaller signature (confirmed by 8 YARA rules) explains the process-injection and LSASS-access signals: PyInstaller bundles Python code and uses legitimate runtime unpacking that can mimic malware behaviour. The file's medium prevalence (133 submitters, 36 days old) and a community researcher's 'Clean' assessment further suggest this is a benign or suspicious application rather than confirmed malware. The absence of tier-1 family consensus, malicious children, and malicious host contact argues against a remote-access trojan.

Key signals · 5

Each signal cites a concrete token from the evidence the arbiter saw — engine name, MITRE technique, signer string, or an exact count.

  1. engines: 3/70 malicious, all low-trust tier (APEX, Bkav, Cylance); tier1Malicious=0; onlyLowTrustFlagging=true

  2. yaraify: 8 rules matched, including 'Detect_PyInstaller' and 'PyInstaller' — file is PyInstaller-compiled executable

  3. behaviour: offensiveCount=2 (T1055, T1486) but hasMaliciousSandboxVerdict=false, droppedChildren.hasMaliciousChild=false (0/10), contactedHosts.maliciousHosts=none

  4. prevalence: medium (133 submitters, 163 submissions, 36 days old) — not rare/new; community comment reports 'Clean' verdict

  5. signing: unsigned; no signer history; no brand mismatch detected

Points in its favour
  • All 16 tier-1 antivirus engines silent — no high-trust malware detection
  • No malicious sandbox verdict recorded
  • All 10 dropped children inspected, zero malicious verdicts
  • Contacted hosts not in our malicious cache (CDN IPs)
  • Medium prevalence (133 submitters) — not a brand-new rare sample; community researcher reported 'Clean'
Points against
  • Unsigned executable — no publisher identity verification
  • Process-injection detected (T1055) — could indicate code obfuscation or malware, but consistent with PyInstaller unpacking
  • LSASS access detected — credential-dumper heuristic fired, but no malicious sandbox verdict
  • Direct-IP C2 contact (no DNS) — evasion indicator, but contacted IPs are legitimate CDN providers
  • Low-trust-only detections — no tier-1 engine consensus
What to do

Treat this file as suspicious pending further investigation. If it is a known legitimate Python application, the detections are likely false positives. If the source is unknown or untrusted, isolate and do not execute. Monitor for any malicious behaviour; the absence of tier-1 consensus and malicious runtime activity suggests low immediate risk, but the offensive MITRE techniques warrant caution.

Threat family attribution

DebuggerCheck API corroborated by 1 source

  • 8 YARA rules
    DebuggerCheck__API, DebuggerException__SetConsoleCtrl, Detect_PyInstaller
Sources disagree

1 contradiction resolved by the scoring engine

Only low-trust / heuristic engines flagged this file
3 engines from the heuristic / generic-AI set flagged it. No tier-1 engine agreed.
Detection weight reduced in scoring.
Runtime behaviour

What this file did when executed

This file was detonated in 1 sandbox and its runtime behaviour was observed.

MITRE ATT&CK
16

Adversary techniques mapped to the MITRE ATT&CK framework.

T1027T1027.002T1033T1055T1057T1059T1070.006T1071T1082T1083T1129T1202T1486T1497T1497.001T1574
Spawned processes
9
$(unnamed)
"C:\Users\<USER>\Desktop\NepTunnel 2.2.exe"
$(unnamed)
C:\Windows\system32\cmd.exe /c "ver"
$(unnamed)
C:\Windows\system32\services.exe
$(unnamed)
C:\Windows\System32\svchost.exe -k NetworkService -p
$(unnamed)
C:\Windows\system32\svchost.exe -k UnistackSvcGroup
$(unnamed)
C:\Windows\System32\svchost.exe -k LocalSystemNetworkRestricted -p -s StorSvc
$(unnamed)
C:\Windows\system32\lsass.exe
$(unnamed)
C:\Windows\system32\svchost.exe -k LocalService -s W32Time
+1 more processes captured.
Network activity
2
IP addresses2
  • 104.18.14.72
  • 199.232.192.193
Filesystem & mutexes
15
Files written15
  • C:\Users\<USER>\AppData\Local\Temp\_MEI55242\PIL\_avif.cp314-win_amd64.pyd
  • C:\Users\<USER>\AppData\Local\Temp\_MEI55242\PIL\_imaging.cp314-win_amd64.pyd
  • C:\Users\<USER>\AppData\Local\Temp\_MEI55242\PIL\_imagingcms.cp314-win_amd64.pyd
  • C:\Users\<USER>\AppData\Local\Temp\_MEI55242\PIL\_imagingft.cp314-win_amd64.pyd
  • C:\Users\<USER>\AppData\Local\Temp\_MEI55242\PIL\_imagingmath.cp314-win_amd64.pyd
+10 more
Dropped payload

Files this sample writes at runtime

This file drops 10 children at runtime. None are currently flagged malicious in our cache.

10 unseen
  • 48f4a239c25354f0e9f817ecedNever scanned
    never seen before
  • 3271d39d7b4dcd841e8eefe5e5Never scanned
    never seen before
  • cb71909bf01a3a7a4c73d46e13Never scanned
    never seen before
  • 6a99bc0128e0c7d6cbbfcbc6c8Never scanned
    never seen before
  • 98074c85650a420a095ab084e9Never scanned
    never seen before
  • 81eca6840b87f2def9fcd7aaaaNever scanned
    never seen before
  • 4f05f31ca026bbfeeee47ab5deNever scanned
    never seen before
  • 3130bf26da0c840c1e025a3539Never scanned
    never seen before
  • 47576cae321c80e69c7fac6b91Never scanned
    never seen before
  • 165be658ab7d61ffc3dfd3acd7Never scanned
    never seen before
External threat intelligence

1 corroborating signal from researcher-curated sources

YARAify HIT·8 community rules matchedView on YARAify
  • DebuggerCheck__API
  • DebuggerException__SetConsoleCtrl
  • Detect_PyInstallerby Obscurity Labs LLC
    Detects PyInstaller compiled executables across platforms
  • golang_bin_JCorn_CSC846by Justin Cornwell
    CSC-846 Golang detection ruleset
  • PyInstallerby @bartblaze
    Identifies executable converted using PyInstaller. This rule by itself does NOT necessarily mean the detected file is malicious.
Cross-referenced against MalwareBazaar (abuse.ch), YARAify, and the CIRCL hashlookup reference DB.
Signature matches

YARA + heuristic rules that fired

A researcher-curated or high-severity heuristic rule matched this sample. These rules target specific malware families and are near-definitive.

5 YARAify3 synthesis
MITRE ATT&CK profile
Defense evasion× 1Cred access× 1C2× 1
YARAify (community)
Researcher-authored rules via abuse.ch
  • DebuggerCheck__API
  • DebuggerException__SetConsoleCtrl
  • Detect_PyInstaller
  • golang_bin_JCorn_CSC846
  • PyInstaller
MalwareTips synthesis rules
Our heuristics on VT data + sandbox behaviour
  • ProcessInjectionhigh

    MITRE T1055 (Process Injection) observed — CreateRemoteThread / APC / reflective-DLL injection. The payload is being smuggled into a legitimate process to bypass AV hooks.

    Evidence
    C:\Windows\System32\svchost.exe -k NetworkService -p
  • CredentialDumpermedium

    Sandbox observed process activity targeting LSASS (Windows credential store). Legitimate software has no business reading LSASS memory — this is Mimikatz-shape behaviour.

    Evidence
    C:\Windows\system32\lsass.exe
  • DirectIpC2medium

    Sample contacted 2 external IP address(es) and zero domains. Benign software virtually always uses DNS; no-DNS direct-IP C2 is a strong malware indicator because it bypasses reputation systems and dodges domain-based blocklists.

    Evidence
    104.18.14.72 · 199.232.192.193
Antivirus engine breakdown

3 detections across 75 engines

3 malicious0 suspicious72 clean
Tier-117 engines
0flag
Top commercial AVs (low FP rate)
Tier-238 engines
0flag
Mainstream engines with mixed FP rates
Low-trust20 engines
3flag
Heuristic / generic-AI engines (high FP rate)
APEX
malicious
Malicious
Bkav
malicious
W32.Malware.FCFFC750
Cylance
malicious
Unsafe
Hash 41b01a63bcb9… cross-referenced against 75 AV engines via our AV network.
PE forensics

Section entropy & packers

Section-level entropy and packer detection from the PE header. Nothing suspicious here — entropy is within the normal range for unpacked code.

ent 8.00Unpacked
Section entropy7 sections
.text
6.47
.rdata
5.75
.data
1.82
.pdata
5.32
.fptable
0.00
.rsrc
7.99
.reloc
5.26
0.0Packed threshold 7.28.0
Prevalence

How often this file shows up in the wild

Moderate prevalence — neither rare nor common. No strong prior applies.

Medium
Unique uploaders
133
Hundreds of people have uploaded this — common.
Total submissions
163
Includes repeat uploads by the same source.
First seen by VT
1mo ago
May 24, 2026
Prevalence quadrant
Rare · New
Targeted malware lives here
Common · New
Just-released software
Rare · Old
Niche or internal tooling
Common · Old
Trusted legitimate binaries
File identity

Forensic fingerprint

File biography
First seen (VT)
5/24/2026, 8:35:33 AM
First seen (MalwareBazaar)
Last analysis (VT)
6/26/2026, 1:00:08 AM
Scanned here
6/29/2026, 2:07:42 AM
File name
NepTunnel 2.2.exe
Size
19.09 MB
MIME type
(unknown)
Detected type
Win32 EXE
SHA-256
41b01a63bcb94d3466ada5e9df375ab92cd777377270aebd09597740bc9f2402
MD5
271d8a10cd69696c2a3f8369893a1ca4
SHA-1
0e9a151c6585c1164a2d893e58af2f623d76f788
PE imphash
dcaf48c1f10b0efa0a4472200f3850ed
First seen (VT)
5/24/2026, 8:35:33 AM
Last analysis (VT)
6/26/2026, 1:00:08 AM
First scan (MalwareTips)
6/29/2026, 2:07:42 AM
Last scan (MalwareTips)
6/29/2026, 2:07:42 AM
Behavior tags
peexe64bitsoverlay
Community classification

Reviews & malware reports(0)

Tell the community what you saw. Tag the sample — Trojan, Adware, False Positive — and share what the file did on your system. Your report helps confirm or dispute the AV verdict.

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