MalwareBazaar Database

You are currently viewing the MalwareBazaar entry for SHA256 55aac3a0ab90b91703fa5b60f8b60f25c94993c8d1ab380298ebf6e1db2dff44. 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: 55aac3a0ab90b91703fa5b60f8b60f25c94993c8d1ab380298ebf6e1db2dff44
SHA3-384 hash: b8223f12417fc47c760711abae870c3c71ac370fb49f68ff743dba721c1b46d893ab272bfceb5c2e002dd248b2c167a2
SHA1 hash: 4ef4f1dbc809dfa6029b9c4919e6b49c5be263a8
MD5 hash: 8bd2afd623eec679db9a9f9a1aed7fa5
humanhash: arkansas-oranges-nine-cold
File name:default.dat
Download: download sample
Signature Efimer
Create hunting rule
File size:14'313'547 bytes
First seen:2026-07-14 17:52:08 UTC
Last seen:Never
File type:Executable exe
MIME type:application/x-dosexec
imphash dcaf48c1f10b0efa0a4472200f3850ed (283 x Efimer, 60 x BlankGrabber, 22 x NetSupport)
ssdeep 393216:vcj+UDM4arXuncJUW63HeXMCHWUjXScuI3/PGTAI:v+jDM4arXu6XMb8XvH/O7
TLSH T1D3E633885AD012EEE8B38238EEC15596F525F4B637B2C6DF0B6453A16C531D04E3EB1B
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 78fcf8f8fcf8e048 (1 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
Link:
https://research.acce.ciphertechsolutions.com/results/3659449d-704d-466a-ba32-b7f3f69cc722/
Detection:
n/a
Link:
https://www.capesandbox.com/analysis/74669/
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=6a56779456bd89099b554565
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/6a567780475d87db3b3822b3/reports/2fed8b66-cd26-4080-8e10-acf4fde9ce7e/overview
Verdict:
Malicious
Labled as:
Yogi.Generic
Link:
https://www.hybrid-analysis.com/sample/55aac3a0ab90b91703fa5b60f8b60f25c94993c8d1ab380298ebf6e1db2dff44
Verdict:
Malicious
File Type:
exe x64
First seen:
2026-07-14T15:07:00Z UTC
Last seen:
2026-07-14T15:29:00Z UTC
Hits:
~10
Link:
https://opentip.kaspersky.com/55aac3a0ab90b91703fa5b60f8b60f25c94993c8d1ab380298ebf6e1db2dff44/results?tab=lookup
Verdict:
Unknown
Link:
https://analyze.intezer.com/analyses/33c5e6b2-e085-4323-9825-770e5c179824
Result
Threat name:
n/a
Detection:
malicious
Classification:
evad
Score:
72 / 100
Link:
https://www.joesandbox.com/analysis/1942411
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: 1942411 Sample: default.dat.exe Startdate: 14/07/2026 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 21 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 29->59
Score:
100%
Verdict:
Malware
File Type:
PE
Link:
https://malprob.io/report/55aac3a0ab90b91703fa5b60f8b60f25c94993c8d1ab380298ebf6e1db2dff44
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/8bd2afd623eec679db9a9f9a1aed7fa5
Detection:
n/a
Link:
https://mwdb.cert.pl/sample/55aac3a0ab90b91703fa5b60f8b60f25c94993c8d1ab380298ebf6e1db2dff44/
Threat name:
Win64.Malware.Yogi
Create hunting rule
Status:
Malicious
First seen:
2026-07-14 17:54:07 UTC
File Type:
PE+ (Exe)
Extracted files:
482
AV detection:
8 of 36 (22.22%)
Threat level:
  2/5
Detection(s):
Suspicious file
Link:
https://check.spamhaus.org/check/?searchterm=kwvmhiflsc4roa72lnqprnqpexeute6i2gvtqauy5p3odwzn75ca._file
Result
Malware family:
n/a
Score:
  8/10
Tags:
execution pyarmor pyinstaller
Link:
https://tria.ge/reports/260714-wgbbtacx3v/
Behaviour
Suspicious behavior: EnumeratesProcesses
Suspicious use of AdjustPrivilegeToken
Suspicious use of WriteProcessMemory
Loads dropped DLL
Command and Scripting Interpreter: PowerShell
Unpacked files
SH256 hash:
55aac3a0ab90b91703fa5b60f8b60f25c94993c8d1ab380298ebf6e1db2dff44
MD5 hash:
8bd2afd623eec679db9a9f9a1aed7fa5
SHA1 hash:
4ef4f1dbc809dfa6029b9c4919e6b49c5be263a8
Link:
https://www.unpac.me/results/865d0f17-7379-44c9-b57a-d53f833efaea/
SH256 hash:
36585912e5eaf83ba9fea0631534f690ccdc2d7ba91537166fe53e56c221e153
MD5 hash:
862f820c3251e4ca6fc0ac00e4092239
SHA1 hash:
ef96d84b253041b090c243594f90938e9a487a9a
Link:
https://www.unpac.me/results/865d0f17-7379-44c9-b57a-d53f833efaea/
SH256 hash:
a5c6a329698490a035133433928d04368ce6285bb91a9d074fc285de4c9a32a4
MD5 hash:
16855ebef31c5b1ebe767f1c617645b3
SHA1 hash:
315521f3a748abfa35cd4d48e8dd09d0556d989b
Link:
https://www.unpac.me/results/865d0f17-7379-44c9-b57a-d53f833efaea/
SH256 hash:
c882b45a926bec656ea43d68b5e12034e6966c36f20ef5516f67a015bf82cf21
MD5 hash:
156e69bf7da6f911cfcc929795f40cd4
SHA1 hash:
aa2e10d46968efaef1a36381b5ae3b8de57ac364
Link:
https://www.unpac.me/results/865d0f17-7379-44c9-b57a-d53f833efaea/
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/55aac3a0ab90b91703fa5b60f8b60f25c94993c8d1ab380298ebf6e1db2dff44

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 55aac3a0ab90b91703fa5b60f8b60f25c94993c8d1ab380298ebf6e1db2dff44

(this sample)

  
Delivery method
Distributed via web download
Cape
Cape
https://www.capesandbox.com/analysis/74669/

Comments