MalwareBazaar Database

You are currently viewing the MalwareBazaar entry for SHA256 52a961e6e33da2febb2efad5c66b07ca4b3c322da9e04a39d8e86239d4fd81b8. 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: 52a961e6e33da2febb2efad5c66b07ca4b3c322da9e04a39d8e86239d4fd81b8
SHA3-384 hash: 987921756c932a0fde226d4c4d61833d8eebef92da8f47506e6a475210d4eeeb4cfec263b23d4e4f31af8e93cf08cbc8
SHA1 hash: 6d360baf43aa810fe0b24967f48e99397e3b88ca
MD5 hash: 3fc0e74e8c3216a4b7dc30d7c65d91ac
humanhash: zebra-ten-gee-lithium
File name:default.dat
Download: download sample
Signature Efimer
Create hunting rule
File size:14'330'275 bytes
First seen:2026-07-13 03:52:12 UTC
Last seen:Never
File type:Executable exe
MIME type:application/x-dosexec
imphash dcaf48c1f10b0efa0a4472200f3850ed (250 x Efimer, 60 x BlankGrabber, 22 x NetSupport)
ssdeep 393216:kJrS3VmPDTAjfmSXMCHWUjXxcuI3/PGTAI:kw3VkDTAr1XMb8XmH/O7
TLSH T1CFE6330CA7D016EEEAB3107DEED546A3F591B4764F31C5EB979892969E0B0D0CC39B02
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 71d89ea292c6f471 (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/5ba1c28b-6853-44c9-807d-8b091b5cbbd3/
Detection:
n/a
Link:
https://www.capesandbox.com/analysis/74392/
Detection(s):
SecuriteInfo.com.Variant.Dropper.354.UNOFFICIAL
Create hunting rule

Verdict:
Malicious
Score:
94.9%
Link:
https://cyber-fortress.com/docs/result/index.php?id=6a546108a53b0ea1c820ee7a
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/6a54610006685bef930c4b4b/reports/d9f3a35a-6e28-4541-b2af-cabc754ccff7/overview
Verdict:
Malicious
Labled as:
Yogi.Generic
Link:
https://www.hybrid-analysis.com/sample/52a961e6e33da2febb2efad5c66b07ca4b3c322da9e04a39d8e86239d4fd81b8
Verdict:
Malicious
File Type:
exe x64
First seen:
2026-07-13T01:10:00Z UTC
Last seen:
2026-07-13T01:42:00Z UTC
Hits:
~10
Link:
https://opentip.kaspersky.com/52a961e6e33da2febb2efad5c66b07ca4b3c322da9e04a39d8e86239d4fd81b8/results?tab=lookup
Verdict:
Unknown
Link:
https://analyze.intezer.com/analyses/81fdd4cb-3c82-4467-a218-8250a81e2a48
Result
Threat name:
n/a
Detection:
malicious
Classification:
evad
Score:
72 / 100
Link:
https://www.joesandbox.com/analysis/1941322
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: 1941322 Sample: default.dat.exe Startdate: 13/07/2026 Architecture: WINDOWS Score: 72 56 Multi AV Scanner detection for submitted file 2->56 58 Joe Sandbox ML detected suspicious sample 2->58 60 Sigma detected: Powershell Base64 Encoded MpPreference Cmdlet 2->60 62 Sigma detected: Suspicious Script Execution From Temp Folder 2->62 8 default.dat.exe 31 2->8         started        12 svchost.exe 1 1 2->12         started        process3 dnsIp4 46 C:\Users\user\AppData\...\unicodedata.pyd, PE32+ 8->46 dropped 48 C:\Users\user\AppData\Local\...\select.pyd, PE32+ 8->48 dropped 50 C:\Users\user\AppData\Local\...\python313.dll, PE32+ 8->50 dropped 52 15 other files (none is malicious) 8->52 dropped 66 Adds a directory exclusion to Windows Defender 8->66 68 Found pyInstaller with non standard icon 8->68 15 default.dat.exe 1 8->15         started        54 127.0.0.1 unknown unknown 12->54 file5 signatures6 process7 signatures8 72 Adds a directory exclusion to Windows Defender 15->72 18 cmd.exe 1 15->18         started        21 cmd.exe 1 15->21         started        23 cmd.exe 1 15->23         started        25 9 other processes 15->25 process9 signatures10 64 Adds a directory exclusion to Windows Defender 18->64 27 powershell.exe 23 18->27         started        30 conhost.exe 18->30         started        32 powershell.exe 23 21->32         started        34 conhost.exe 21->34         started        36 powershell.exe 23 23->36         started        38 conhost.exe 23->38         started        40 powershell.exe 25->40         started        42 powershell.exe 25->42         started        44 16 other processes 25->44 process11 signatures12 70 Loading BitLocker PowerShell Module 32->70
Score:
99%
Verdict:
Malware
File Type:
PE
Link:
https://malprob.io/report/52a961e6e33da2febb2efad5c66b07ca4b3c322da9e04a39d8e86239d4fd81b8
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/3fc0e74e8c3216a4b7dc30d7c65d91ac
Detection:
n/a
Link:
https://mwdb.cert.pl/sample/52a961e6e33da2febb2efad5c66b07ca4b3c322da9e04a39d8e86239d4fd81b8/
Threat name:
Win64.Malware.Yogi
Create hunting rule
Status:
Malicious
First seen:
2026-07-13 03:53:52 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=kkuwdzxdhwrp5ozo7lk4m2yhzjftymrnvhqeuooy5brdtvh5qg4a._file
Result
Malware family:
n/a
Score:
  8/10
Tags:
execution pyarmor pyinstaller
Link:
https://tria.ge/reports/260713-efb4aabx5k/
Behaviour
Suspicious behavior: EnumeratesProcesses
Suspicious use of AdjustPrivilegeToken
Suspicious use of WriteProcessMemory
Loads dropped DLL
Command and Scripting Interpreter: PowerShell
Unpacked files
SH256 hash:
52a961e6e33da2febb2efad5c66b07ca4b3c322da9e04a39d8e86239d4fd81b8
MD5 hash:
3fc0e74e8c3216a4b7dc30d7c65d91ac
SHA1 hash:
6d360baf43aa810fe0b24967f48e99397e3b88ca
Link:
https://www.unpac.me/results/1e3af307-61d3-4a4a-aa74-c1c8cf7f9f70/
SH256 hash:
36585912e5eaf83ba9fea0631534f690ccdc2d7ba91537166fe53e56c221e153
MD5 hash:
862f820c3251e4ca6fc0ac00e4092239
SHA1 hash:
ef96d84b253041b090c243594f90938e9a487a9a
Link:
https://www.unpac.me/results/1e3af307-61d3-4a4a-aa74-c1c8cf7f9f70/
SH256 hash:
484ebdd4ddb9587d7a1ebecd5e89af444c1bccc13c8779e6fe024ea3699c231a
MD5 hash:
c649069fcffdcf1bad334903ee0f059a
SHA1 hash:
2340628c7106112f37308a59c536e881267632eb
Link:
https://www.unpac.me/results/1e3af307-61d3-4a4a-aa74-c1c8cf7f9f70/
SH256 hash:
a5c6a329698490a035133433928d04368ce6285bb91a9d074fc285de4c9a32a4
MD5 hash:
16855ebef31c5b1ebe767f1c617645b3
SHA1 hash:
315521f3a748abfa35cd4d48e8dd09d0556d989b
Link:
https://www.unpac.me/results/1e3af307-61d3-4a4a-aa74-c1c8cf7f9f70/
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/52a961e6e33da2febb2efad5c66b07ca4b3c322da9e04a39d8e86239d4fd81b8

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 52a961e6e33da2febb2efad5c66b07ca4b3c322da9e04a39d8e86239d4fd81b8

(this sample)

  
Delivery method
Distributed via web download
Cape
Cape
https://www.capesandbox.com/analysis/74392/

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