isrstealer | b877b7de1b96f28deab0077de2e79040f0bd0677c4b05083e145862ee44f70e2

General

Target
b877b7de1b96f28deab0077de2e79040f0bd0677c4b05083e145862ee44f70e2.exe
Size 272KB
Sample220308-jmsf3acgf3
SHA256 b877b7de1b96f28deab0077de2e79040f0bd0677c4b05083e145862ee44f70e2
MD5 96d7f0167137bf38582a97df1c8f86a3
SHA1 09b6cb16c01e0611940f47a2ac3082e6ec710bde
SHA512 cdcd9ca7513a0b05d9e75b31f3b5a9524e044c1e0ad4437a34a257a2378edb4dd98e4b3f79efbb88f49b8cd439bbf7d21d57c98cbee6e6f42b0b3645c7354f0a
MD5 SHA1 SHA512

Score

10^/10

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

ISR Stealer Payload 3 IoCs

Executes dropped EXE 2 IoCs

pid	Process
552	payment.exe
1328	payment.exe

UPX packed file 3 IoCs

Detects executables packed with UPX/modified UPX open source packer.

resource	yara_rule
behavioral2/memory/1328-139-0x0000000000400000-0x0000000000453000-memory.dmp	upx
behavioral2/memory/1328-142-0x0000000000400000-0x0000000000453000-memory.dmp	upx
behavioral2/memory/1328-143-0x0000000000400000-0x0000000000453000-memory.dmp	upx

Checks computer location settings 2 TTPs 1 IoCs

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

Query Registry

System Information Discovery

description	ioc	Process
Key value queried	\REGISTRY\USER\S-1-5-21-1346565761-3498240568-4147300184-1000\Control Panel\International\Geo\Nation	b877b7de1b96f28deab0077de2e79040f0bd0677c4b05083e145862ee44f70e2.exe

Reads user/profile data of web browsers 2 TTPs
Infostealers often target stored browser data, which can include saved credentials etc.
spyware stealer

Data from Local System
T1005

Credentials in Files
T1081

Suspicious use of SetThreadContext 1 IoCs

description	pid	Process	procid_target
PID 552 set thread context of 1328	552	payment.exe	87

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

System Information Discovery
T1082

Suspicious use of SetWindowsHookEx 1 IoCs

pid	Process
552	payment.exe

Suspicious use of WriteProcessMemory 18 IoCs

description	pid	Process	procid_target
PID 1268 wrote to memory of 2348	1268	b877b7de1b96f28deab0077de2e79040f0bd0677c4b05083e145862ee44f70e2.exe	80
PID 1268 wrote to memory of 2348	1268	b877b7de1b96f28deab0077de2e79040f0bd0677c4b05083e145862ee44f70e2.exe	80
PID 1268 wrote to memory of 2348	1268	b877b7de1b96f28deab0077de2e79040f0bd0677c4b05083e145862ee44f70e2.exe	80
PID 1268 wrote to memory of 4952	1268	b877b7de1b96f28deab0077de2e79040f0bd0677c4b05083e145862ee44f70e2.exe	84
PID 1268 wrote to memory of 4952	1268	b877b7de1b96f28deab0077de2e79040f0bd0677c4b05083e145862ee44f70e2.exe	84
PID 4952 wrote to memory of 3964	4952	cmd.exe	85
PID 4952 wrote to memory of 3964	4952	cmd.exe	85
PID 4952 wrote to memory of 552	4952	cmd.exe	86
PID 4952 wrote to memory of 552	4952	cmd.exe	86
PID 4952 wrote to memory of 552	4952	cmd.exe	86
PID 552 wrote to memory of 1328	552	payment.exe	87
PID 552 wrote to memory of 1328	552	payment.exe	87
PID 552 wrote to memory of 1328	552	payment.exe	87
PID 552 wrote to memory of 1328	552	payment.exe	87
PID 552 wrote to memory of 1328	552	payment.exe	87
PID 552 wrote to memory of 1328	552	payment.exe	87
PID 552 wrote to memory of 1328	552	payment.exe	87
PID 552 wrote to memory of 1328	552	payment.exe	87

Views/modifies file attributes 1 TTPs 1 IoCs

evasion

Hidden Files and Directories

pid	Process
3964	attrib.exe

C:\Users\Admin\AppData\Local\Temp\b877b7de1b96f28deab0077de2e79040f0bd0677c4b05083e145862ee44f70e2.exe
"C:\Users\Admin\AppData\Local\Temp\b877b7de1b96f28deab0077de2e79040f0bd0677c4b05083e145862ee44f70e2.exe"
1⤵
- Checks computer location settings
- Suspicious use of WriteProcessMemory
PID:1268
- C:\Windows\SysWOW64\cmd.exe
  C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\is64.bat" "
  2⤵
  PID:2348
- C:\Windows\system32\cmd.exe
  "C:\Windows\Sysnative\cmd.exe" /C C:\Users\Admin\AppData\Local\Temp\ytmp\t16434.bat "C:\Users\Admin\AppData\Local\Temp\b877b7de1b96f28deab0077de2e79040f0bd0677c4b05083e145862ee44f70e2.exe"
  2⤵
  - Suspicious use of WriteProcessMemory
  PID:4952
- - C:\Windows\system32\attrib.exe
    attrib +h C:\Users\Admin\AppData\Local\Temp\ytmp
    3⤵
    - Views/modifies file attributes
    PID:3964
- - C:\Users\Admin\AppData\Local\Temp\afolder\payment.exe
    payment.exe
    3⤵
    - Executes dropped EXE
    - Suspicious use of SetThreadContext
    - Suspicious use of SetWindowsHookEx
    - Suspicious use of WriteProcessMemory
    PID:552
  - - C:\Users\Admin\AppData\Local\Temp\afolder\payment.exe
      /scomma "C:\Users\Admin\AppData\Local\Temp\tmp.ini"
      4⤵
      Executes dropped EXE
      PID:1328