MalwareBazaar Database

You are currently viewing the MalwareBazaar entry for SHA256 b8cef8210aea4e212d3cfea0f3f7755417d7f11ef974c037fe2a6d5c779a4c2e. While MalwareBazaar tries to identify whether the sample provided is malicious or not, there is no guarantee that a sample in MalwareBazaar is malicious.

Database Entry



Efimer


Vendor detections: 11


Intelligence 11 IOCs YARA 7 File information Comments

SHA256 hash: b8cef8210aea4e212d3cfea0f3f7755417d7f11ef974c037fe2a6d5c779a4c2e
SHA3-384 hash: 6eebf01c1c70c55198a45b8833abe6f27c14935e8706133596750ea04c0cfca81b1f2c706dbc8add9e2ee0c2adfebc44
SHA1 hash: 8b5aa725b07bf56a0e714b07fc7f050b5791731d
MD5 hash: 15509f512a9bc85dcee6a0215460b9a8
humanhash: cardinal-jig-golf-jig
File name:default.dat
Download: download sample
Signature Efimer
File size:14'298'123 bytes
First seen:2026-07-15 16:52:12 UTC
Last seen:Never
File type:Executable exe
MIME type:application/x-dosexec
imphash dcaf48c1f10b0efa0a4472200f3850ed (471 x Efimer, 60 x BlankGrabber, 22 x SalatStealer)
ssdeep 393216:X8QpScpsddPdTidBXMCHWUjXocuI3/PGTAI:XJSceTwXMb8XdH/O7
TLSH T12DE6334C66E006EEE2A78039ADF292C6F56874A15B72C9EF135886353E570F14E39733
TrID 37.0% (.EXE) Win64 Executable (generic) (6522/11/2)
28.6% (.EXE) Win16 NE executable (generic) (5038/12/1)
11.5% (.EXE) OS/2 Executable (generic) (2029/13)
11.3% (.EXE) Generic Win/DOS Executable (2002/3)
11.3% (.EXE) DOS Executable (generic) (2000/1)
Magika pebin
dhash icon 7071e4d6a6e4f030 (8 x Efimer)
Reporter aachum
Tags:ClickFix Efimer exe


Avatar
iamaachum
https://tuasesoriadigital.es/default.dat

Intelligence


File Origin
# of uploads :
1
# of downloads :
156
Origin country :
ES ES
Vendor Threat Intelligence
Malware configuration found for:
PyInstaller
Details
Verdict:
Malicious
Score:
94.9%
Tags:
installer shell sage
Verdict:
Likely Malicious
Threat level:
  7.5/10
Confidence:
100%
Tags:
anti-debug expand installer-heuristic lolbin masquerade microsoft_visual_cc overlay packed packed packed pyinstaller reconnaissance
Verdict:
Malicious
File Type:
exe x64
First seen:
2026-07-15T20:33:00Z UTC
Last seen:
2026-07-17T06:06:00Z UTC
Hits:
~10
Result
Threat name:
n/a
Detection:
malicious
Classification:
evad
Score:
76 / 100
Signature
Adds a directory exclusion to Windows Defender
Contains functionality to infect the boot sector
Found pyInstaller with non standard icon
Joe Sandbox ML detected suspicious sample
Loading BitLocker PowerShell Module
Multi AV Scanner detection for submitted file
Sigma detected: Powershell Base64 Encoded MpPreference Cmdlet
Sigma detected: Suspicious Script Execution From Temp Folder
Behaviour
Behavior Graph:
behaviorgraph top1 signatures2 2 Behavior Graph ID: 1943025 Sample: default.dat.exe Startdate: 15/07/2026 Architecture: WINDOWS Score: 76 51 Multi AV Scanner detection for submitted file 2->51 53 Joe Sandbox ML detected suspicious sample 2->53 55 Sigma detected: Powershell Base64 Encoded MpPreference Cmdlet 2->55 57 Sigma detected: Suspicious Script Execution From Temp Folder 2->57 8 default.dat.exe 31 2->8         started        process3 file4 43 C:\Users\user\AppData\...\unicodedata.pyd, PE32+ 8->43 dropped 45 C:\Users\user\AppData\Local\...\select.pyd, PE32+ 8->45 dropped 47 C:\Users\user\AppData\Local\...\python313.dll, PE32+ 8->47 dropped 49 15 other files (none is malicious) 8->49 dropped 61 Contains functionality to infect the boot sector 8->61 63 Adds a directory exclusion to Windows Defender 8->63 65 Found pyInstaller with non standard icon 8->65 12 default.dat.exe 1 8->12         started        signatures5 process6 signatures7 67 Adds a directory exclusion to Windows Defender 12->67 15 cmd.exe 1 12->15         started        18 cmd.exe 1 12->18         started        20 cmd.exe 1 12->20         started        22 9 other processes 12->22 process8 signatures9 69 Adds a directory exclusion to Windows Defender 15->69 24 powershell.exe 23 15->24         started        27 conhost.exe 15->27         started        29 powershell.exe 23 18->29         started        31 conhost.exe 18->31         started        33 powershell.exe 23 20->33         started        35 conhost.exe 20->35         started        37 powershell.exe 22->37         started        39 powershell.exe 22->39         started        41 16 other processes 22->41 process10 signatures11 59 Loading BitLocker PowerShell Module 24->59
Verdict:
inconclusive
YARA:
5 match(es)
Tags:
Executable PDB Path PE (Portable Executable) PE File Layout Win 64 Exe x64
Threat name:
Win64.Trojan.Malgent
Status:
Malicious
First seen:
2026-07-15 16:53:41 UTC
File Type:
PE+ (Exe)
Extracted files:
482
AV detection:
10 of 24 (41.67%)
Threat level:
  5/5
Result
Malware family:
n/a
Score:
  8/10
Tags:
execution pyarmor pyinstaller
Behaviour
Suspicious behavior: EnumeratesProcesses
Suspicious use of AdjustPrivilegeToken
Suspicious use of WriteProcessMemory
Loads dropped DLL
Command and Scripting Interpreter: PowerShell
Unpacked files
SH256 hash:
b8cef8210aea4e212d3cfea0f3f7755417d7f11ef974c037fe2a6d5c779a4c2e
MD5 hash:
15509f512a9bc85dcee6a0215460b9a8
SHA1 hash:
8b5aa725b07bf56a0e714b07fc7f050b5791731d
SH256 hash:
36585912e5eaf83ba9fea0631534f690ccdc2d7ba91537166fe53e56c221e153
MD5 hash:
862f820c3251e4ca6fc0ac00e4092239
SHA1 hash:
ef96d84b253041b090c243594f90938e9a487a9a
SH256 hash:
a5c6a329698490a035133433928d04368ce6285bb91a9d074fc285de4c9a32a4
MD5 hash:
16855ebef31c5b1ebe767f1c617645b3
SHA1 hash:
315521f3a748abfa35cd4d48e8dd09d0556d989b
SH256 hash:
b88ec186759a968dd86bd9323d554cfa982c56f4896058b64b9af46a3018dcfb
MD5 hash:
c078ab42d6525e96ad30b49f9f3cd2fb
SHA1 hash:
61660c955e3c6fe06af83a9ae16f43a8f85cc3fc
Please note that we are no longer able to provide a coverage score for Virus Total.

YARA Signatures


MalwareBazaar uses YARA rules from several public and non-public repositories, such as YARAhub and Malpedia. Those are being matched against malware samples uploaded to MalwareBazaar as well as against any suspicious process dumps they may create. Please note that only results from TLP:CLEAR rules are being displayed.

Rule name:DebuggerCheck__API
Reference:https://github.com/naxonez/yaraRules/blob/master/AntiDebugging.yara
Rule name:DebuggerException__SetConsoleCtrl
Reference:https://github.com/naxonez/yaraRules/blob/master/AntiDebugging.yara
Rule name:Detect_PyInstaller
Author:Obscurity Labs LLC
Description:Detects PyInstaller compiled executables across platforms
Rule name:golang_bin_JCorn_CSC846
Author:Justin Cornwell
Description:CSC-846 Golang detection ruleset
Rule name:PyInstaller
Author:@bartblaze
Description:Identifies executable converted using PyInstaller. This rule by itself does NOT necessarily mean the detected file is malicious.
Rule name:TH_AntiVM_MassHunt_Win_Malware_2026_CYFARE
Author:CYFARE
Description:Detects Windows malware employing anti-VM / anti-sandbox evasion techniques across VMware, VirtualBox, Hyper-V, QEMU, Xen, and generic sandbox environments
Reference:https://cyfare.net/
Rule name:upxHook
Author:@r3dbU7z
Description:Detect artifacts from 'upxHook' - modification of UPX packer
Reference:https://bazaar.abuse.ch/sample/6352be8aa5d8063673aa428c3807228c40505004320232a23d99ebd9ef48478a/

File information


The table below shows additional information about this malware sample such as delivery method and external references.

Web download

Efimer

Executable exe b8cef8210aea4e212d3cfea0f3f7755417d7f11ef974c037fe2a6d5c779a4c2e

(this sample)

  
Delivery method
Distributed via web download

Comments