isrstealer | 39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c

Resubmissions

16/03/2025, 00:38

250316-ay6cmawzbx 10

15/03/2025, 23:37

250315-3mc6xszmv2 10

Analysis

max time kernel
102s
max time network
122s
platform
windows10-2004_x64
resource
win10v2004-20250313-en
resource tags

arch:x64arch:x86image:win10v2004-20250313-enlocale:en-usos:windows10-2004-x64system
submitted
15/03/2025, 23:37

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General

Target

39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe
Size

164KB
MD5

761bcf1d315a442b1281f5d0f8ce4fa6
SHA1

e4a9586d926514f198ee1ee4cd8725721ffa234f
SHA256

39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c
SHA512

1310ef76ae4b638c4cc6574cb3d7e24f69dc7b59581b4c3f60814072e9446d61d55b69ba69c22509c9d587d5328a1fff28469a4beb6a93625befddbe6213f313
SSDEEP

3072:TY3W224yAIM6H/vOXoE1EMuXnD7KHmL4OnA:0G4yzRUoE1QXyO

Score

10^/10

isrstealer bootkit discovery persistence spyware stealer trojan

Malware Config

Signatures

ISR Stealer
ISR Stealer is a modified version of Hackhound Stealer written in visual basic.
trojan stealer isrstealer

ISR Stealer payload 4 IoCs

resource	yara_rule
behavioral2/memory/5532-2-0x0000000000400000-0x000000000040B000-memory.dmp	family_isrstealer
behavioral2/memory/5532-4-0x0000000000400000-0x000000000040B000-memory.dmp	family_isrstealer
behavioral2/memory/5532-7-0x0000000000400000-0x000000000040B000-memory.dmp	family_isrstealer
behavioral2/memory/5532-10-0x0000000000400000-0x000000000040B000-memory.dmp	family_isrstealer

Isrstealer family
isrstealer
Reads user/profile data of web browsers 3 TTPs
Infostealers often target stored browser data, which can include saved credentials etc.
spyware stealer

Data from Local System
T1005

Credentials In Files
T1552.001

Credentials from Web Browsers
T1555.003

Writes to the Master Boot Record (MBR) 1 TTPs 1 IoCs

Bootkits write to the MBR to gain persistence at a level below the operating system.

bootkit persistence

Bootkit

T1542.003

description	ioc	Process
File opened for modification	\??\PhysicalDrive0	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe

Suspicious use of SetThreadContext 1 IoCs

description	pid	Process	procid_target
PID 3540 set thread context of 5532	3540	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe	87

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

System Information Discovery
T1082

Program crash 1 IoCs

pid	pid_target	Process	procid_target
2608	5532	WerFault.exe	87

System Location Discovery: System Language Discovery 1 TTPs 2 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	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe

Suspicious use of SetWindowsHookEx 2 IoCs

pid	Process
3540	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe
5532	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe

Suspicious use of WriteProcessMemory 8 IoCs

description	pid	Process	procid_target
PID 3540 wrote to memory of 5532	3540	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe	87
PID 3540 wrote to memory of 5532	3540	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe	87
PID 3540 wrote to memory of 5532	3540	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe	87
PID 3540 wrote to memory of 5532	3540	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe	87
PID 3540 wrote to memory of 5532	3540	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe	87
PID 3540 wrote to memory of 5532	3540	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe	87
PID 3540 wrote to memory of 5532	3540	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe	87
PID 3540 wrote to memory of 5532	3540	39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe	87

C:\Users\Admin\AppData\Local\Temp\39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe
"C:\Users\Admin\AppData\Local\Temp\39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe"
1⤵
- Writes to the Master Boot Record (MBR)
- Suspicious use of SetThreadContext
- System Location Discovery: System Language Discovery
- Suspicious use of SetWindowsHookEx
- Suspicious use of WriteProcessMemory
PID:3540
- C:\Users\Admin\AppData\Local\Temp\39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe
  "C:\Users\Admin\AppData\Local\Temp\39cef98c230cfed0768fa061c1c42bd32080b7c1725cb43f9068b711749e8f3c.exe"
  2⤵
  - System Location Discovery: System Language Discovery
  - Suspicious use of SetWindowsHookEx
  PID:5532
- - C:\Windows\SysWOW64\WerFault.exe
    C:\Windows\SysWOW64\WerFault.exe -u -p 5532 -s 764
    3⤵
    - Program crash
    PID:2608

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 376 -p 5532 -ip 5532
1⤵
PID:5144

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Persistence

Pre-OS Boot

T1542

Bootkit

T1542.003

Privilege Escalation

Defense Evasion

Pre-OS Boot

T1542

Bootkit

T1542.003

Credential Access

Credentials from Password Stores

T1555

Credentials from Web Browsers

T1555.003

Unsecured Credentials

T1552

Credentials In Files

T1552.001

Discovery

System Information Discovery

T1082

System Location Discovery

T1614

System Language Discovery

T1614.001

Lateral Movement

Collection

Data from Local System

T1005

Command and Control

Exfiltration

Impact

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Downloads

memory/5532-2-0x0000000000400000-0x000000000040B000-memory.dmp

Filesize
44KB

Download
memory/5532-4-0x0000000000400000-0x000000000040B000-memory.dmp

Filesize
44KB

Download
memory/5532-7-0x0000000000400000-0x000000000040B000-memory.dmp

Filesize
44KB

Download
memory/5532-10-0x0000000000400000-0x000000000040B000-memory.dmp

Filesize
44KB

Download

Resubmissions

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads