Analysis
- max time kernel
148s - max time network
138s - platform
ubuntu-18.04_amd64 - resource
ubuntu1804-amd64-20260513-en - resource tags
arch:amd64arch:i386image:ubuntu1804-amd64-20260513-enkernel:4.15.0-213-genericlocale:en-usos:ubuntu-18.04-amd64system - submitted
19/08/2026, 02:55
Behavioral task
behavioral1
Sample
putita.x86.elf
Resource
ubuntu1804-amd64-20260513-en
General
- Target putita.x86.elf
- Size 88KB
- Sample260819-dev94avhle
- SHA256 a6f29739da9fc810562cedf1c39604be9e7aa84fca1b2d794957ce5fe8a871de
- MD5 0d9992e426a9b621a9c61a2ea7cf6121
- SHA1 4df1ce328599f603dff6cf32039ea6ac717dca8c
- SHA512 dab4ce9bbc5e3a7aa2b447b716bb8c148948302ea4ee922469733134d3c0728411b7a333e6f19c46e6455b75e1986099c8f62b9055586ec0b607c5801ff02786
- SSDEEP 1536:s4HT1ZoKt+yJRwNOz+MRaA9KBJMCg2yjiTyVkEWOqm4iJ9FSnnouy8DMr:s4zFt1cAwjMCg2CeyCEZqm1onoutDMr
- TLSH T139930237DC590729C18C647BB4FEFD05A00DD72DCA8146DD26AC74B68CD2BA8248B69E
- MD5 SHA1 SHA512 SSDEEP TLSH
Malware Config
Signatures
- Deletes itself 1 IoCs
pid Process 1490 putita.x86.elf - Creates/modifies Cron job 1 TTPs 1 IoCs
Cron allows running tasks on a schedule, and is commonly used for malware persistence.
description ioc Process File opened for modification /var/spool/cron/crontabs/tmp.vtsK7V crontab - Creates/modifies environment variables 1 TTPs 8 IoCs
Creating/modifying environment variables is a common persistence mechanism.
description ioc Process File opened for modification /home/pi/.bashrc putita.x86.elf File opened for modification /home/pi/.profile putita.x86.elf File opened for modification /root/.bashrc putita.x86.elf File opened for modification /root/.profile putita.x86.elf File opened for modification /etc/profile putita.x86.elf File opened for modification /etc/bash.bashrc putita.x86.elf File opened for modification /home/admin/.bashrc putita.x86.elf File opened for modification /home/admin/.profile putita.x86.elf -
description ioc Process File opened for modification /etc/init.d/kworker-helper putita.x86.elf - Modifies rc script 2 TTPs 1 IoCs
Adding/modifying system rc scripts is a common persistence mechanism.
description ioc Process File opened for modification /etc/rc.local putita.x86.elf - Modifies systemd 2 TTPs 1 IoCs
Adds/ modifies systemd service files. Likely to achieve persistence.
description ioc Process File opened for modification /etc/systemd/system/kworker-helper.service putita.x86.elf - Modifies Bash startup script 2 TTPs 8 IoCs
description ioc Process File opened for modification /root/.profile putita.x86.elf File opened for modification /etc/profile putita.x86.elf File opened for modification /etc/bash.bashrc putita.x86.elf File opened for modification /home/admin/.bashrc putita.x86.elf File opened for modification /home/admin/.profile putita.x86.elf File opened for modification /home/pi/.bashrc putita.x86.elf File opened for modification /home/pi/.profile putita.x86.elf File opened for modification /root/.bashrc putita.x86.elf -
resource yara_rule behavioral1/files/fstream-1.dat upx - Changes its process name 1 IoCs
description pid Process Changes the process name, possibly in an attempt to hide itself 1490 putita.x86.elf -
description ioc Process File opened for reading /proc/self/exe putita.x86.elf
Processes
-
/tmp/putita.x86.elf/tmp/putita.x86.elf1⤵
- Deletes itself
- Creates/modifies environment variables
- Modifies init.d
- Modifies rc script
- Modifies systemd
- Modifies Bash startup script
- Changes its process name
- Reads runtime system information
PID:1490 -
/bin/shsh -c "crontab -l 2>/dev/null"2⤵PID:1491
-
/usr/bin/crontabcrontab -l3⤵PID:1492
-
-
-
/bin/shsh -c "(crontab -l 2>/dev/null; echo '@reboot /usr/lib/kworker-helper') | crontab - 2>/dev/null"2⤵PID:1493
-
/usr/bin/crontabcrontab -3⤵
- Creates/modifies Cron job
PID:1495
-
-
/usr/bin/crontabcrontab -l3⤵PID:1496
-
-
-
/usr/bin/chattrchattr +i /etc/init.d/kworker-helper1⤵PID:1499
-
/usr/bin/chattrchattr +i /etc/systemd/system/kworker-helper.service1⤵PID:1498
-
/usr/bin/chattrchattr +i /usr/lib/kworker-helper1⤵PID:1497
-
/bin/busyboxchattr +i /usr/lib/kworker-helper1⤵PID:1500
-
/bin/busyboxchattr +i /etc/init.d/kworker-helper1⤵PID:1502
-
/bin/busyboxchattr +i /etc/systemd/system/kworker-helper.service1⤵PID:1501
Network
MITRE ATT&CK Enterprise v16
Persistence
Boot or Logon Autostart Execution
4XDG Autostart Entries
1Boot or Logon Initialization Scripts
2RC Scripts
2Create or Modify System Process
1Systemd Service
1Event Triggered Execution
1Unix Shell Configuration Modification
1Hijack Execution Flow
1Path Interception by PATH Environment Variable
1Scheduled Task/Job
1Cron
1Privilege Escalation
Boot or Logon Autostart Execution
4XDG Autostart Entries
1Boot or Logon Initialization Scripts
2RC Scripts
2Create or Modify System Process
1Systemd Service
1Event Triggered Execution
1Unix Shell Configuration Modification
1Hijack Execution Flow
1Path Interception by PATH Environment Variable
1Scheduled Task/Job
1Cron
1Replay Monitor
Loading Replay Monitor...
Downloads
- Path /etc/init.d/kworker-helper
- Size 379B
- SHA256 daeb1a39fa3bf6fad15573d3aba269ac40fd43532bb487be2ed13453756cbe50
- MD5 c38d603241c783cc32e445061d3c1a14
- SHA1 65ec284d9c12bff79813b2f164900351e12512ac
- SHA512 54eedceecdb7fb3a56d9187df635e48654933657309b6e6fd0dc23c29850668278e88e21e046e83c91c1e81c0ce14236c8bdcfe09bab01dd820999c4c95c5f93
- TLSH T153E0D892164D7B3E1E0500B1DA04E7C5D8428D09622AE426B04C17E35BAB747D8755AC
- MD5 SHA1 SHA512 TLSH
- Path /etc/systemd/system/kworker-helper.service
- Size 190B
- SHA256 dcc492c83b938187ae12ae6df39f2350a98bb80761d79aa3ad4f29fa9a371c07
- MD5 ed6dfe7a7cad02f20eabc83ecc6e2563
- SHA1 b160b2a13238257fe4c233118f5152e38a8297d3
- SHA512 8ee7d7d57e9976b9d75bf37739ecdff2c1c003ea0d5e42d979b72dd64e1b424bb5b71d4d7a37c712fa13d9fc9c62156902a5c324007159b75a9e691d27d80be0
- TLSH T155C02232170120E0D80F39F24E97AB008D100A0487CEF0200BC0104B44E2A824431EA9
- MD5 SHA1 SHA512 TLSH
- Path /root/.ashrc
- Size 61B
- SHA256 30fc62ecc4fde897502efdd4821bd14c60694b758b6664f4044cfd48ca3a2efb
- MD5 7ba24613596abdadc60214554a375aed
- SHA1 b83e4b71eaa248f3849936053713453e3c7c3943
- SHA512 1930e566a15a91af54614d2b291dcacb4ad7a942dcfd1d301cd2c439139d79691688586df8d6ce294f0b292092b9e0d9a2146a8f30929bf102794520390170cc
- MD5 SHA1 SHA512
- Path /usr/lib/kworker-helper
- Size 88KB
- SHA256 a6f29739da9fc810562cedf1c39604be9e7aa84fca1b2d794957ce5fe8a871de
- MD5 0d9992e426a9b621a9c61a2ea7cf6121
- SHA1 4df1ce328599f603dff6cf32039ea6ac717dca8c
- SHA512 dab4ce9bbc5e3a7aa2b447b716bb8c148948302ea4ee922469733134d3c0728411b7a333e6f19c46e6455b75e1986099c8f62b9055586ec0b607c5801ff02786
- SSDEEP 1536:s4HT1ZoKt+yJRwNOz+MRaA9KBJMCg2yjiTyVkEWOqm4iJ9FSnnouy8DMr:s4zFt1cAwjMCg2CeyCEZqm1onoutDMr
- TLSH T139930237DC590729C18C647BB4FEFD05A00DD72DCA8146DD26AC74B68CD2BA8248B69E
- MD5 SHA1 SHA512 SSDEEP TLSH
- Path /var/spool/cron/crontabs/tmp.vtsK7V
- Size 207B
- SHA256 b1d300c8e921ac0807698f958902fd8483f8b7eea4950bdb2142567f9f02a7e1
- MD5 40e363eba6198aeb1c2182c43043c37a
- SHA1 48161371b66a0cb4434a79befa08531ffb3d07fa
- SHA512 13065b21fed5825b3126effc040bee65410071c7b70d8829a48cf3ff62e1f870d91ed7022f23711cf175e0c54bcb6bb2d9050c8214313dde1904a895e80311d4
- TLSH T155D0221CBF0027706D842B86251E0B1CFC91982CC04EEE10E2DC202683426CC7B50D62
- MD5 SHA1 SHA512 TLSH