typeentityconfidencemediumcreated2026-06-01updated2026-06-05malware-familyloaderdefense-evasionc2evasion

54e64e

OpenCTI opaque family label. Currently a single-sample family: a MSVC C++ x64 dropper masquerading as a system-analyzer tool.

Overview

The 54e64e label is assigned by OpenCTI/MalwareBazaar as a family identifier for a Windows loader/dropper cluster. As of 2026-06-01 only one sample has been analysed: a 5.2 MB MSVC C++ PE that behaves as a masqueraded "System Analyzer Tool" which downloads a second-stage payload, disables Windows Defender, and executes the payload. OpenCTI also co-labels this sample dropped-by-amadey, suggesting it is part of the Amadey downloader delivery chain, though this relationship is not independently confirmed.

Build Stack

Two distinct build morphs observed within the same family label:

Morph 1 — Null-padded MSVC C++ (3b13b28c)

  • Compiler: MSVC 19.43 (Visual Studio 2022 17.3+) ^[/intel/analyses/3b13b28ca3a6d3c82228f5cc6a6e0bef583e9c3b3092da4c20fe72c75f3dd386.html]
  • Language: C++ with full MSVC standard library (STL strings, streams, exception support)
  • Packing/Obfuscation: None. No packer, no strip, no encryption. Binary is padded to ~5 MB with null bytes after a small overlay UAC manifest.
  • Signing: Unsigned

Morph 2 — UPX-packed x64 (c8db13c1)

  • Packer: UPX (3 sections: UPX0, UPX1, UPX2) with modified/hacked header that defeats standard UPX decompression. ^[/intel/analyses/c8db13c15ad99cc002dda644384e730497972a9995510918f5fc7e2c071b9a0f.html]
  • Compiler: Unknown — timestamp zeroed by UPX
  • Import table: Stripped to four KERNEL32 functions (LoadLibraryA, GetProcAddress, VirtualProtect, ExitProcess) rebuilt at runtime
  • Signing: Unsigned
  • Payload indicators: AES S-Box tables found inside compressed UPX1 section, suggesting encrypted second-stage content

Deploy / TTPs

Technique ATT&CK ID Evidence
Ingress Tool Transfer T1105 URLDownloadToFileW to fetch http://80.253.249.169:5000/upfevb.exe
Impair Defenses T1562.001 Spawns hidden powershell Add-MpPreference -ExclusionPath
Virtualization/Sandbox Evasion T1497.001 PRNG-based delay loop and verbose fake diagnostic output
Signed Binary Proxy Execution T1218.011 ShellExecuteA to launch downloaded payload
User Execution T1204.002 PE GUI executable, user-launched
Bypass UAC T1548.002 Admin gate via AllocateAndInitializeSid + CheckTokenMembership
Match Legitimate Name or Location T1036.005 Masquerades as "System Analyzer Tool v4.2.1"

Variants / Aliases

  • Amadey dropper (unconfirmed upstream relationship; OpenCTI co-label: dropped-by-amadey)
  • Build artifact name: certpert (from PDB path)

Notable Analyses

  • raw/analyses/3b13b28ca3a6d3c82228f5cc6a6e0bef583e9c3b3092da4c20fe72c75f3dd386 — Deep static analysis; static-only (CAPE skipped). Null-padded MSVC C++ "certpert" dropper with fake diagnostic masquerade, Defender exclusion via PowerShell, HTTP payload fetch.
  • raw/analyses/c8db13c15ad99cc002dda644384e730497972a9995510918f5fc7e2c071b9a0f — UPX-packed x64 sibling with modified/hacked packer. Three sections, four KERNEL32 imports, compressed payload with AES S-Box indicators. Standard UPX decompression fails. Static-only (CAPE skipped).
  • raw/analyses/cc4aa789cf0c80b32004b90be6be0ad80944ad85730c6095cc3ca29469059503Third morph: Go 1.25.4 PE64 infostealer. Signed DV cert CN=askart.com, 24 randomized main.* functions, GUI subsystem, no .rsrc, no hardcoded C2. Matches golang-stealer-build-pattern and unclassified-go-pe64 cluster; not build-related to prior MSVC siblings. Static-only (CAPE skipped).

Capabilities

  • admin-rights-gate-sid-check
  • prng-delay-loop-evasion
  • fake-diagnostic-output-masquerade
  • http-payload-download
  • defender-exclusion-powershell
  • shell-execute-dropped-payload
  • upx-compression-with-modified-header
  • runtime-import-table-rebuild
  • go-infostealer-randomized-function-names
  • authenticode-signing-throwaway-dv-cert
  • gui-subsystem-no-window-code
  • runtime-c2-resolution-no-hardcoded-ioc