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Linux Analysis Report
shell64.elf

Overview

General Information

Sample name:	shell64.elf
Analysis ID:	1563084
MD5:	7913c2e7505fd7b75c8e4facd9037247
SHA1:	b4612b30731ba3d3a94d4160e173df7d88917bf2
SHA256:	1e15f4423af7008e883565eba1f9f03f48f3a7b2b0fcf52521bebcc6a14a2eca
Tags:	elfmalwaremetasploituser-Joker
Infos:

Detection

ConnectBack

Score:	68
Range:	0 - 100
Whitelisted:	false

Signatures

Found malware configuration

Multi AV Scanner detection for submitted file

Yara detected ConnectBack

Machine Learning detection for sample

Detected TCP or UDP traffic on non-standard ports

Executes the "rm" command used to delete files or directories

Sample contains only a LOAD segment without any section mappings

Tries to connect to HTTP servers, but all servers are down (expired dropper behavior)

Classification

General Information

Joe Sandbox version:	41.0.0 Charoite
Analysis ID:	1563084
Start date and time:	2024-11-26 13:41:08 +01:00
Joe Sandbox product:	CloudBasic
Overall analysis duration:	0h 4m 19s
Hypervisor based Inspection enabled:	false
Report type:	full
Cookbook file name:	defaultlinuxfilecookbook.jbs
Analysis system description:	Ubuntu Linux 20.04 x64 (Kernel 5.4.0-72, Firefox 91.0, Evince Document Viewer 3.36.10, LibreOffice 6.4.7.2, OpenJDK 11.0.11)
Analysis Mode:	default
Sample name:	shell64.elf
Detection:	MAL
Classification:	mal68.troj.linELF@0/0@0/0

Warnings

VT rate limit hit for: shell64.elf

Runtime Messages

Command:	/tmp/shell64.elf
PID:	6214
Exit Code:	139
Exit Code Info:	SIGSEGV (11) Segmentation fault invalid memory reference
Killed:	False
Standard Output:
Standard Error:

Process Tree

system is lnxubuntu20

dash New Fork (PID: 6203, Parent: 4331)

rm (PID: 6203, Parent: 4331, MD5: aa2b5496fdbfd88e38791ab81f90b95b) Arguments: rm -f /tmp/tmp.t4tFzjNclW /tmp/tmp.iWebozjp6s /tmp/tmp.MJnQnHEcZ1

dash New Fork (PID: 6204, Parent: 4331)

rm (PID: 6204, Parent: 4331, MD5: aa2b5496fdbfd88e38791ab81f90b95b) Arguments: rm -f /tmp/tmp.t4tFzjNclW /tmp/tmp.iWebozjp6s /tmp/tmp.MJnQnHEcZ1

shell64.elf (PID: 6214, Parent: 6129, MD5: 7913c2e7505fd7b75c8e4facd9037247) Arguments: /tmp/shell64.elf

cleanup

Malware Threat Intel

Provided by

Name	Description	Attribution	Blogpost URLs	Link
ConnectBack	ConnectBack malware is a type of malicious software designed to establish unauthorized connections from an infected system to a remote server. Once a victim's device is compromised, ConnectBack creates a covert channel for communication, allowing the attacker to remotely control and gather sensitive information from the compromised system.	No Attribution	https://labs.sucuri.net/signatures/malwares/pl-backdoor-connectback-001/	https://malpedia.caad.fkie.fraunhofer.de/details/elf.connectback

Yara Signatures

Initial Sample

Source	Rule	Description	Author	Strings
shell64.elf	JoeSecurity_ConnectBack	Yara detected ConnectBack	Joe Security

Memory Dumps

Source	Rule	Description	Author	Strings
6214.1.0000000000400000.0000000000401000.rwx.sdmp	JoeSecurity_ConnectBack	Yara detected ConnectBack	Joe Security

Suricata Signatures

⊘No Suricata rule has matched

Joe Sandbox Signatures

Click to jump to signature section

Show All Signature Results

AV Detection

Found malware configuration

Source: shell64.elf

Malware Configuration Extractor: ConnectBack {"C2": "45.43.36.223:44444"}

Multi AV Scanner detection for submitted file

Source: shell64.elf

ReversingLabs: Detection: 50%

Machine Learning detection for sample

Source: shell64.elf

Joe Sandbox ML: detected

Source: global traffic

TCP traffic: 192.168.2.23:33050 -> 45.43.36.223:44444

Source: global traffic	TCP traffic: 192.168.2.23:43928 -> 91.189.91.42:443
Source: global traffic	TCP traffic: 192.168.2.23:42836 -> 91.189.91.43:443
Source: global traffic	TCP traffic: 192.168.2.23:42516 -> 109.202.202.202:80

Source: unknown	TCP traffic detected without corresponding DNS query: 45.43.36.223
Source: unknown	TCP traffic detected without corresponding DNS query: 45.43.36.223
Source: unknown	TCP traffic detected without corresponding DNS query: 91.189.91.42
Source: unknown	TCP traffic detected without corresponding DNS query: 45.43.36.223
Source: unknown	TCP traffic detected without corresponding DNS query: 45.43.36.223
Source: unknown	TCP traffic detected without corresponding DNS query: 91.189.91.43
Source: unknown	TCP traffic detected without corresponding DNS query: 109.202.202.202
Source: unknown	TCP traffic detected without corresponding DNS query: 91.189.91.42
Source: unknown	TCP traffic detected without corresponding DNS query: 91.189.91.43
Source: unknown	TCP traffic detected without corresponding DNS query: 109.202.202.202
Source: unknown	TCP traffic detected without corresponding DNS query: 91.189.91.42

Source: unknown	Network traffic detected: HTTP traffic on port 43928 -> 443
Source: unknown	Network traffic detected: HTTP traffic on port 42836 -> 443

Source: LOAD without section mappings

Program segment: 0x400000

Source: classification engine

Classification label: mal68.troj.linELF@0/0@0/0

Source: /usr/bin/dash (PID: 6203)	Rm executable: /usr/bin/rm -> rm -f /tmp/tmp.t4tFzjNclW /tmp/tmp.iWebozjp6s /tmp/tmp.MJnQnHEcZ1			Jump to behavior
Source: /usr/bin/dash (PID: 6204)	Rm executable: /usr/bin/rm -> rm -f /tmp/tmp.t4tFzjNclW /tmp/tmp.iWebozjp6s /tmp/tmp.MJnQnHEcZ1			Jump to behavior

Stealing of Sensitive Information

Yara detected ConnectBack

Source: Yara match	File source: shell64.elf, type: SAMPLE
Source: Yara match	File source: 6214.1.0000000000400000.0000000000401000.rwx.sdmp, type: MEMORY

Remote Access Functionality

Yara detected ConnectBack

Source: Yara match	File source: shell64.elf, type: SAMPLE
Source: Yara match	File source: 6214.1.0000000000400000.0000000000401000.rwx.sdmp, type: MEMORY

Mitre Att&ck Matrix

Reconnaissance	Resource Development	Initial Access	Execution	Persistence	Privilege Escalation	Defense Evasion	Credential Access	Discovery	Lateral Movement	Collection	Command and Control	Exfiltration	Impact
Gather Victim Identity Information	Acquire Infrastructure	Valid Accounts	Windows Management Instrumentation	Path Interception	Path Interception	1 File Deletion	OS Credential Dumping	System Service Discovery	Remote Services	Data from Local System	1 Encrypted Channel	Exfiltration Over Other Network Medium	Abuse Accessibility Features
Credentials	Domains	Default Accounts	Scheduled Task/Job	Boot or Logon Initialization Scripts	Boot or Logon Initialization Scripts	Rootkit	LSASS Memory	Application Window Discovery	Remote Desktop Protocol	Data from Removable Media	1 Non-Standard Port	Exfiltration Over Bluetooth	Network Denial of Service
Email Addresses	DNS Server	Domain Accounts	At	Logon Script (Windows)	Logon Script (Windows)	Obfuscated Files or Information	Security Account Manager	Query Registry	SMB/Windows Admin Shares	Data from Network Shared Drive	1 Application Layer Protocol	Automated Exfiltration	Data Encrypted for Impact

Malware Configuration

Threatname: ConnectBack

{"C2": "45.43.36.223:44444"}

Behavior Graph

Hide Legend

Legend:

Process
Signature
Created File
DNS/IP Info
Is Dropped
Number of created Files
Is malicious
Internet

Screenshots

Thumbnails

This section contains all screenshots as thumbnails, including those not shown in the slideshow.

Antivirus, Machine Learning and Genetic Malware Detection

Initial Sample

Source	Detection	Scanner	Label	Link
shell64.elf	50%	ReversingLabs	Linux.Backdoor.ConnectBack
shell64.elf	100%	Joe Sandbox ML

Dropped Files

⊘No Antivirus matches

Domains

⊘No Antivirus matches

URLs

⊘No Antivirus matches

Domains and IPs

Contacted Domains

⊘No contacted domains info

World Map of Contacted IPs

No. of IPs < 25%
25% < No. of IPs < 50%
50% < No. of IPs < 75%
75% < No. of IPs

Public IPs

IP	Domain	Country	ASN	ASN Name	Malicious
109.202.202.202	unknown	Switzerland	13030	INIT7CH	false
45.43.36.223	unknown	United States	135377	UHGL-AS-APUCloudHKHoldingsGroupLimitedHK	true
91.189.91.43	unknown	United Kingdom	41231	CANONICAL-ASGB	false
91.189.91.42	unknown	United Kingdom	41231	CANONICAL-ASGB	false

Joe Sandbox View / Context

IPs

Match	Associated Sample Name / URL	SHA 256	Detection	Threat Name	Link	Context
109.202.202.202	kpLwzBouH4.elf	Get hash	malicious	Unknown	Browse	ch.archive.ubuntu.com/ubuntu/pool/main/f/firefox/firefox_92.0%2bbuild3-0ubuntu0.20.04.1_amd64.deb
91.189.91.43	dlr.m68k.elf	Get hash	malicious	Unknown	Browse
	dlr.spc.elf	Get hash	malicious	Unknown	Browse
	dlr.mips.elf	Get hash	malicious	Mirai, Okiru	Browse
	dlr.ppc.elf	Get hash	malicious	Unknown	Browse
	dlr.x86.elf	Get hash	malicious	Mirai, Okiru	Browse
	dlr.sh4.elf	Get hash	malicious	Unknown	Browse
	dlr.arm6.elf	Get hash	malicious	Mirai, Okiru	Browse
	dlr.arm5.elf	Get hash	malicious	Unknown	Browse
	la.bot.arc.elf	Get hash	malicious	Mirai	Browse
91.189.91.42	dlr.m68k.elf	Get hash	malicious	Unknown	Browse
	dlr.spc.elf	Get hash	malicious	Unknown	Browse
	dlr.mips.elf	Get hash	malicious	Mirai, Okiru	Browse
	dlr.ppc.elf	Get hash	malicious	Unknown	Browse
	dlr.x86.elf	Get hash	malicious	Mirai, Okiru	Browse
	dlr.sh4.elf	Get hash	malicious	Unknown	Browse
	dlr.arm6.elf	Get hash	malicious	Mirai, Okiru	Browse
	dlr.arm5.elf	Get hash	malicious	Unknown	Browse
	la.bot.arc.elf	Get hash	malicious	Mirai	Browse

Domains

⊘No context

ASNs

Match	Associated Sample Name / URL	SHA 256	Detection	Threat Name	Link	Context
CANONICAL-ASGB	dlr.m68k.elf	Get hash	malicious	Unknown	Browse	91.189.91.42
	dlr.spc.elf	Get hash	malicious	Unknown	Browse	91.189.91.42
	dlr.mips.elf	Get hash	malicious	Mirai, Okiru	Browse	91.189.91.42
	dlr.ppc.elf	Get hash	malicious	Unknown	Browse	91.189.91.42
	dlr.x86.elf	Get hash	malicious	Mirai, Okiru	Browse	91.189.91.42
	dlr.sh4.elf	Get hash	malicious	Unknown	Browse	91.189.91.42
	dlr.arm6.elf	Get hash	malicious	Mirai, Okiru	Browse	91.189.91.42
	dlr.arm5.elf	Get hash	malicious	Unknown	Browse	91.189.91.42
	la.bot.arc.elf	Get hash	malicious	Mirai	Browse	91.189.91.42
CANONICAL-ASGB	dlr.m68k.elf	Get hash	malicious	Unknown	Browse	91.189.91.42
	dlr.spc.elf	Get hash	malicious	Unknown	Browse	91.189.91.42
	dlr.mips.elf	Get hash	malicious	Mirai, Okiru	Browse	91.189.91.42
	dlr.ppc.elf	Get hash	malicious	Unknown	Browse	91.189.91.42
	dlr.x86.elf	Get hash	malicious	Mirai, Okiru	Browse	91.189.91.42
	dlr.sh4.elf	Get hash	malicious	Unknown	Browse	91.189.91.42
	dlr.arm6.elf	Get hash	malicious	Mirai, Okiru	Browse	91.189.91.42
	dlr.arm5.elf	Get hash	malicious	Unknown	Browse	91.189.91.42
	la.bot.arc.elf	Get hash	malicious	Mirai	Browse	91.189.91.42
INIT7CH	dlr.m68k.elf	Get hash	malicious	Unknown	Browse	109.202.202.202
	dlr.spc.elf	Get hash	malicious	Unknown	Browse	109.202.202.202
	dlr.mips.elf	Get hash	malicious	Mirai, Okiru	Browse	109.202.202.202
	dlr.ppc.elf	Get hash	malicious	Unknown	Browse	109.202.202.202
	dlr.x86.elf	Get hash	malicious	Mirai, Okiru	Browse	109.202.202.202
	dlr.sh4.elf	Get hash	malicious	Unknown	Browse	109.202.202.202
	dlr.arm6.elf	Get hash	malicious	Mirai, Okiru	Browse	109.202.202.202
	dlr.arm5.elf	Get hash	malicious	Unknown	Browse	109.202.202.202
	la.bot.arc.elf	Get hash	malicious	Mirai	Browse	109.202.202.202
UHGL-AS-APUCloudHKHoldingsGroupLimitedHK	XFO-E2024-013 SMP-10.3-F01-2210 Host spare parts.exe	Get hash	malicious	FormBook, PureLog Stealer	Browse	107.155.56.30
	Swift copy.exe	Get hash	malicious	FormBook	Browse	107.155.56.30
	SecuriteInfo.com.Trojan.GenericKD.72343208.3006.1077.exe	Get hash	malicious	Unknown	Browse	152.32.197.201
	SecuriteInfo.com.Trojan.GenericKD.72343208.3006.1077.exe	Get hash	malicious	Unknown	Browse	152.32.197.201
	https://rwy.xpbf130.vip/	Get hash	malicious	Unknown	Browse	101.36.121.234
	http://cmn.ftft155.vip/	Get hash	malicious	Unknown	Browse	101.36.121.234
	http://cmn.xfor965.vip/	Get hash	malicious	Unknown	Browse	101.36.121.234
	http://cmn.pkgu192.vip/	Get hash	malicious	Unknown	Browse	101.36.121.234
	http://cmn.jduv311.vip/	Get hash	malicious	Unknown	Browse	101.36.121.234
	http://cmn.gvhu330.vip/	Get hash	malicious	Unknown	Browse	101.36.121.234

JA3 Fingerprints

⊘No context

Dropped Files

⊘No context

Created / dropped Files

⊘No created / dropped files found

Static File Info

General

File type:	ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, no section header
Entropy (8bit):	4.276692563343198
TrID:	ELF Executable and Linkable format (Linux) (4029/14) 50.16% ELF Executable and Linkable format (generic) (4004/1) 49.84%
File name:	shell64.elf
File size:	250 bytes
MD5:	7913c2e7505fd7b75c8e4facd9037247
SHA1:	b4612b30731ba3d3a94d4160e173df7d88917bf2
SHA256:	1e15f4423af7008e883565eba1f9f03f48f3a7b2b0fcf52521bebcc6a14a2eca
SHA512:	ceedfd35f312afe4ee64d6b5c5f7181282578f51c2b35ee25c7e12ca2e874f52a37a94aa7840eaa34b61af338109356d235e3e94f8d6f566c39fdf04c9df0674
SSDEEP:	6:BnX//In8/r1uBxHocmTr6zQ3RQdygg5XJYD:BvwncrAH3mHn532D
TLSH:	E2D080330B0A80DADBD4123F657859DCD77B8A76574966310890DC014C0D6045F52C75
File Content Preview:	.ELF..............>.....x.@.....@...................@.8...........................@.......@.............\|...............1.j.X...H..M1.j"AZj.Z..H..xQj.AYPj)X.j._j.^..H..x;H.H.....-+$.QH..j.Zj*X..YH..y%I..t.Wj#Xj.j.H..H1...YY_H..y.j<Xj._..^j~Z..H..x...

Static ELF Info

ELF header
Class:	ELF64
Data:	2's complement, little endian
Version:	1 (current)
Machine:	Advanced Micro Devices X86-64
Version Number:	0x1
Type:	EXEC (Executable file)
OS/ABI:	UNIX - System V
ABI Version:	0
Entry Point Address:	0x400078
Flags:	0x0
ELF Header Size:	64
Program Header Offset:	64
Program Header Size:	56
Number of Program Headers:	1
Section Header Offset:	0
Section Header Size:	0
Number of Section Headers:	0
Header String Table Index:	0

Program Segments

Type	Offset	Virtual Address	Physical Address	File Size	Memory Size	Entropy	Flags	Flags Description	Align	Prog Interpreter	Section Mappings
LOAD	0x0	0x400000	0x400000	0xfa	0x17c	4.2767	0x7	RWE	0x1000

Network Behavior

Network Port Distribution

TCP Packets

Timestamp	Source Port	Dest Port	Source IP	Dest IP
Nov 26, 2024 13:41:47.705960035 CET	33050	44444	192.168.2.23	45.43.36.223
Nov 26, 2024 13:41:47.826039076 CET	44444	33050	45.43.36.223	192.168.2.23
Nov 26, 2024 13:41:47.826229095 CET	33050	44444	192.168.2.23	45.43.36.223
Nov 26, 2024 13:41:48.211005926 CET	43928	443	192.168.2.23	91.189.91.42
Nov 26, 2024 13:41:50.450555086 CET	44444	33050	45.43.36.223	192.168.2.23
Nov 26, 2024 13:41:50.454602957 CET	33050	44444	192.168.2.23	45.43.36.223
Nov 26, 2024 13:41:50.626249075 CET	33050	44444	192.168.2.23	45.43.36.223
Nov 26, 2024 13:41:50.747162104 CET	44444	33050	45.43.36.223	192.168.2.23
Nov 26, 2024 13:41:53.842297077 CET	42836	443	192.168.2.23	91.189.91.43
Nov 26, 2024 13:41:55.122114897 CET	42516	80	192.168.2.23	109.202.202.202
Nov 26, 2024 13:42:09.968055010 CET	43928	443	192.168.2.23	91.189.91.42
Nov 26, 2024 13:42:20.206587076 CET	42836	443	192.168.2.23	91.189.91.43
Nov 26, 2024 13:42:26.349766016 CET	42516	80	192.168.2.23	109.202.202.202
Nov 26, 2024 13:42:50.922339916 CET	43928	443	192.168.2.23	91.189.91.42

System Behavior

Analysis Process: dash PID: 6203, Parent PID: 4331

General

Start time (UTC):	12:41:39
Start date (UTC):	26/11/2024
Path:	/usr/bin/dash
Arguments:	-
File size:	129816 bytes
MD5 hash:	1e6b1c887c59a315edb7eb9a315fc84c

Chronological Activities

Analysis Process: rm PID: 6203, Parent PID: 4331

General

Start time (UTC):	12:41:39
Start date (UTC):	26/11/2024
Path:	/usr/bin/rm
Arguments:	rm -f /tmp/tmp.t4tFzjNclW /tmp/tmp.iWebozjp6s /tmp/tmp.MJnQnHEcZ1
File size:	72056 bytes
MD5 hash:	aa2b5496fdbfd88e38791ab81f90b95b

Chronological Activities

Analysis Process: dash PID: 6204, Parent PID: 4331

General

Start time (UTC):	12:41:39
Start date (UTC):	26/11/2024
Path:	/usr/bin/dash
Arguments:	-
File size:	129816 bytes
MD5 hash:	1e6b1c887c59a315edb7eb9a315fc84c

Chronological Activities

Analysis Process: rm PID: 6204, Parent PID: 4331

General

Start time (UTC):	12:41:39
Start date (UTC):	26/11/2024
Path:	/usr/bin/rm
Arguments:	rm -f /tmp/tmp.t4tFzjNclW /tmp/tmp.iWebozjp6s /tmp/tmp.MJnQnHEcZ1
File size:	72056 bytes
MD5 hash:	aa2b5496fdbfd88e38791ab81f90b95b

Chronological Activities

Analysis Process: shell64.elf PID: 6214, Parent PID: 6129

General

Start time (UTC):	12:41:46
Start date (UTC):	26/11/2024
Path:	/tmp/shell64.elf
Arguments:	/tmp/shell64.elf
File size:	250 bytes
MD5 hash:	7913c2e7505fd7b75c8e4facd9037247

Description:	Adversaries may delete files left behind by the actions of their intrusion activity. Malware, tools, or other non-native files dropped or created on a system by an adversary (ex: Ingress Tool Transfer ) may leave traces to indicate to what was done within a network and how. Removal of these files can occur during an intrusion, or as part of a post-intrusion process to minimize the adversary's footprint.
Tactics:	Defense Evasion
Data Sources:	Command: Command Execution, File: File Deletion
Platforms:	Linux, macOS, Windows
Url:	Open detailed description by Mitre

Description:	Adversaries may employ a known encryption algorithm to conceal command and control traffic rather than relying on any inherent protections provided by a communication protocol. Despite the use of a secure algorithm, these implementations may be vulnerable to reverse engineering if secret keys are encoded and/or generated within malware samples/configuration files.
Tactics:	Command and Control
Data Sources:	Network Traffic: Network Traffic Content
Platforms:	Linux, macOS, Windows
Url:	Open detailed description by Mitre

Description:	Adversaries may communicate using a protocol and port pairing that are typically not associated. For example, HTTPS over port 8088or port 587as opposed to the traditional port 443. Adversaries may make changes to the standard port used by a protocol to bypass filtering or muddle analysis/parsing of network data.
Tactics:	Command and Control
Data Sources:	Network Traffic: Network Traffic Content, Network Traffic: Network Traffic Flow
Platforms:	Linux, macOS, Windows
Url:	Open detailed description by Mitre

Description:	Adversaries may communicate using OSI application layer protocols to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.
Tactics:	Command and Control
Data Sources:	Network Traffic: Network Traffic Content, Network Traffic: Network Traffic Flow
Platforms:	Linux, macOS, Windows
Url:	Open detailed description by Mitre

Behavior Section

Behavior Chronological

Disassembly

Uncategorized

Graph

Loading Joe Sandbox Report ...

Warning!

Linux Analysis Report shell64.elf

Overview

General Information

Detection

Signatures

Classification

General Information

Warnings

Runtime Messages

Process Tree

Malware Threat Intel

Yara Signatures

Initial Sample

Memory Dumps

Suricata Signatures

Joe Sandbox Signatures

AV Detection

Networking

System Summary

Persistence and Installation Behavior

Stealing of Sensitive Information

Remote Access Functionality

Mitre Att&ck Matrix

Malware Configuration

Threatname: ConnectBack

Behavior Graph

Screenshots

Thumbnails

Antivirus, Machine Learning and Genetic Malware Detection

Initial Sample

Dropped Files

Domains

URLs

Domains and IPs

Contacted Domains

World Map of Contacted IPs

Public IPs

Joe Sandbox View / Context

IPs

Domains

ASNs

JA3 Fingerprints

Dropped Files

Created / dropped Files

Static File Info

General

Static ELF Info

ELF header

Program Segments

Network Behavior

Network Port Distribution

TCP Packets

System Behavior

Analysis Process: dash PID: 6203, Parent PID: 4331

General

Chronological Activities

Analysis Process: rm PID: 6203, Parent PID: 4331

General

Chronological Activities

Analysis Process: dash PID: 6204, Parent PID: 4331

General

Chronological Activities

Analysis Process: rm PID: 6204, Parent PID: 4331

General

Chronological Activities

Analysis Process: shell64.elf PID: 6214, Parent PID: 6129

General

Chronological Activities

Linux Analysis Report
shell64.elf