MalwareBazaar Database

You are currently viewing the MalwareBazaar entry for SHA256 4a338c6ca796c18dea79e298ebd3675703c198af5060a6f18bc7eb07fcd89a8b. 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
Download sample Add tag Delete this sample Report a False Positive

SHA256 hash: 4a338c6ca796c18dea79e298ebd3675703c198af5060a6f18bc7eb07fcd89a8b
SHA3-384 hash: ccc46d32c1e16f19c4c4fe6845838e262d9c06fe5ba58761a8dbd01b08ff750e6ca3306ecec7b200a316408167304773
SHA1 hash: 7c601de7e06ddd56313e3b0223d944692389ecec
MD5 hash: 22fb2d30626d382bf149340e1c05f31f
humanhash: two-triple-montana-muppet
File name:default.dat
Download: download sample
Signature Efimer
Create hunting rule
File size:14'313'239 bytes
First seen:2026-07-13 00:52:16 UTC
Last seen:Never
File type:Executable exe
MIME type:application/x-dosexec
imphash dcaf48c1f10b0efa0a4472200f3850ed (260 x Efimer, 60 x BlankGrabber, 22 x NetSupport)
ssdeep 393216:9o5q+BVoT32L146DVYcXMCHWUjXVcuI3/PGTAI:9TQm32L14C5XMb8XiH/O7
TLSH T12BE6332492D122ADD773A13D7ED152A9D0ACB8B54B32C98F13DC82B17E672E04D3D61B
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 b271e8cccce8f0f0 (1 x Efimer)
Reporter aachum
Tags:ClickFix Efimer exe


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

Intelligence

File Origin
# of uploads :
1
# of downloads :
196
Origin country :
ES ES
Vendor Threat Intelligence
Malware configuration found for:
PyInstaller
Details
Link:
https://research.acce.ciphertechsolutions.com/results/6164587f-6f8e-44b6-b7dc-13fa4de48fa9/
Detection:
n/a
Link:
https://www.capesandbox.com/analysis/74366/
Detection(s):
SecuriteInfo.com.Variant.Dropper.354.UNOFFICIAL
Create hunting rule

Verdict:
Malicious
Score:
97.4%
Link:
https://cyber-fortress.com/docs/result/index.php?id=6a5436d5a53b0ea1c820e9e7
Tags:
installer shell sage
Result
Verdict:
Clean
Maliciousness:

Behaviour
Creating a file in the %temp% subdirectories
Restart of the analyzed sample
Creating a window
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
Link:
https://www.filescan.io/uploads/6a5436cb550b01e7e8bc6cbb/reports/5e3ab7d7-836d-452f-9970-86c5a0f06fe2/overview
Verdict:
Malicious
Labled as:
Yogi.Generic
Link:
https://www.hybrid-analysis.com/sample/4a338c6ca796c18dea79e298ebd3675703c198af5060a6f18bc7eb07fcd89a8b
Verdict:
Malicious
File Type:
exe x64
First seen:
2026-07-12T22:06:00Z UTC
Last seen:
2026-07-12T23:45:00Z UTC
Hits:
~10
Link:
https://opentip.kaspersky.com/4a338c6ca796c18dea79e298ebd3675703c198af5060a6f18bc7eb07fcd89a8b/results?tab=lookup
Verdict:
Unknown
Link:
https://analyze.intezer.com/analyses/15b2cd37-8efc-4b8d-9b7e-91e08c54b6db
Result
Threat name:
n/a
Detection:
malicious
Classification:
evad
Score:
72 / 100
Link:
https://www.joesandbox.com/analysis/1941279
Signature
Adds a directory exclusion to Windows Defender
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:
Download SVG
behaviorgraph top1 signatures2 2 Behavior Graph ID: 1941279 Sample: default.dat.exe Startdate: 13/07/2026 Architecture: WINDOWS Score: 72 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 Adds a directory exclusion to Windows Defender 8->61 63 Found pyInstaller with non standard icon 8->63 12 default.dat.exe 1 8->12         started        signatures5 process6 signatures7 65 Adds a directory exclusion to Windows Defender 12->65 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 67 Adds a directory exclusion to Windows Defender 15->67 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 22 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
Score:
99%
Verdict:
Malware
File Type:
PE
Link:
https://malprob.io/report/4a338c6ca796c18dea79e298ebd3675703c198af5060a6f18bc7eb07fcd89a8b
Verdict:
inconclusive
YARA:
5 match(es)
Tags:
Executable PDB Path PE (Portable Executable) PE File Layout Win 64 Exe x64
Link:
https://app.malva.re/file/22fb2d30626d382bf149340e1c05f31f
Detection:
n/a
Link:
https://mwdb.cert.pl/sample/4a338c6ca796c18dea79e298ebd3675703c198af5060a6f18bc7eb07fcd89a8b/
Threat name:
Win64.Malware.Yogi
Create hunting rule
Status:
Malicious
First seen:
2026-07-13 00:53:48 UTC
File Type:
PE+ (Exe)
Extracted files:
482
AV detection:
9 of 36 (25.00%)
Threat level:
  2/5
Detection(s):
Suspicious file
Link:
https://check.spamhaus.org/check/?searchterm=jizyy3fhs3ay32tz4kmoxu3hk4b4dgfpkbqkn4mly7vqp7gytkfq._file
Result
Malware family:
n/a
Score:
  8/10
Tags:
execution pyarmor pyinstaller
Link:
https://tria.ge/reports/260713-a8a98sav3p/
Behaviour
Suspicious behavior: EnumeratesProcesses
Suspicious use of AdjustPrivilegeToken
Suspicious use of WriteProcessMemory
Loads dropped DLL
Command and Scripting Interpreter: PowerShell
Unpacked files
SH256 hash:
4a338c6ca796c18dea79e298ebd3675703c198af5060a6f18bc7eb07fcd89a8b
MD5 hash:
22fb2d30626d382bf149340e1c05f31f
SHA1 hash:
7c601de7e06ddd56313e3b0223d944692389ecec
Link:
https://www.unpac.me/results/4638f511-9779-4931-af8a-4b65c21cfc04/
SH256 hash:
36585912e5eaf83ba9fea0631534f690ccdc2d7ba91537166fe53e56c221e153
MD5 hash:
862f820c3251e4ca6fc0ac00e4092239
SHA1 hash:
ef96d84b253041b090c243594f90938e9a487a9a
Link:
https://www.unpac.me/results/4638f511-9779-4931-af8a-4b65c21cfc04/
SH256 hash:
8aa150e7bf94509f50fb2da3735eaa4f08351f78b6e081a6d4f907db9206aec3
MD5 hash:
95cbe74af631596a1a75bc5b2dd836bd
SHA1 hash:
cf0e81b231e66efe41d8a16cc620ba8414c5b1e4
Link:
https://www.unpac.me/results/4638f511-9779-4931-af8a-4b65c21cfc04/
SH256 hash:
a5c6a329698490a035133433928d04368ce6285bb91a9d074fc285de4c9a32a4
MD5 hash:
16855ebef31c5b1ebe767f1c617645b3
SHA1 hash:
315521f3a748abfa35cd4d48e8dd09d0556d989b
Link:
https://www.unpac.me/results/4638f511-9779-4931-af8a-4b65c21cfc04/
Please note that we are no longer able to provide a coverage score for Virus Total.
Threat name:
Malicious File
Score:
1.00
Link:
https://yomi.yoroi.company/submissions/4a338c6ca796c18dea79e298ebd3675703c198af5060a6f18bc7eb07fcd89a8b

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
Create hunting rule
Reference:https://github.com/naxonez/yaraRules/blob/master/AntiDebugging.yara
Rule name:DebuggerException__SetConsoleCtrl
Create hunting rule
Reference:https://github.com/naxonez/yaraRules/blob/master/AntiDebugging.yara
Rule name:Detect_PyInstaller
Create hunting rule
Author:Obscurity Labs LLC
Description:Detects PyInstaller compiled executables across platforms
Rule name:golang_bin_JCorn_CSC846
Create hunting rule
Author:Justin Cornwell
Description:CSC-846 Golang detection ruleset
Rule name:PyInstaller
Create hunting rule
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
Create hunting rule
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
Create hunting rule
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 4a338c6ca796c18dea79e298ebd3675703c198af5060a6f18bc7eb07fcd89a8b

(this sample)

  
Delivery method
Distributed via web download
Cape
Cape
https://www.capesandbox.com/analysis/74366/
  
URLhaus
https://urlhaus.abuse.ch/url/3864471/

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