Edit tour

Linux Analysis Report
5544x64.elf

Overview

General Information

Sample name:	5544x64.elf
Analysis ID:	1576279
MD5:	59683c48cdc2f63363942ca921f17af2
SHA1:	df29da5f5e3cbb7a8b34cd036cdedde8d6384b64
SHA256:	561b89228b562c0a0b53b5848a179fac10ae0226706db82e8dd24226da199d94
Tags:	elfmalwaremeterpreteruser-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

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:	1576279
Start date and time:	2024-12-16 17:59:08 +01:00
Joe Sandbox product:	CloudBasic
Overall analysis duration:	0h 4m 22s
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:	5544x64.elf
Detection:	MAL
Classification:	mal68.troj.linELF@0/0@2/0

Warnings

VT rate limit hit for: 5544x64.elf

Runtime Messages

Command:	/tmp/5544x64.elf
PID:	5486
Exit Code:	139
Exit Code Info:	SIGSEGV (11) Segmentation fault invalid memory reference
Killed:	False
Standard Output:
Standard Error:

Process Tree

system is lnxubuntu20

5544x64.elf (PID: 5486, Parent: 5409, MD5: 59683c48cdc2f63363942ca921f17af2) Arguments: /tmp/5544x64.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
5544x64.elf	JoeSecurity_ConnectBack	Yara detected ConnectBack	Joe Security

Memory Dumps

Source	Rule	Description	Author	Strings
5486.1.0000000000400000.0000000000401000.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: 5544x64.elf

Malware Configuration Extractor: ConnectBack {"C2": "45.43.36.223:5544"}

Multi AV Scanner detection for submitted file

Source: 5544x64.elf

ReversingLabs: Detection: 63%

Machine Learning detection for sample

Source: 5544x64.elf

Joe Sandbox ML: detected

Source: global traffic

TCP traffic: 192.168.2.14:34390 -> 45.43.36.223:5544

Source: global traffic

TCP traffic: 192.168.2.14:46540 -> 185.125.190.26:443

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: 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: 185.125.190.26
Source: unknown	TCP traffic detected without corresponding DNS query: 185.125.190.26
Source: unknown	UDP traffic detected without corresponding DNS query: 1.1.1.1
Source: unknown	UDP traffic detected without corresponding DNS query: 1.1.1.1

Source: global traffic

DNS traffic detected: DNS query: daisy.ubuntu.com

Source: unknown

Network traffic detected: HTTP traffic on port 46540 -> 443

Source: LOAD without section mappings

Program segment: 0x400000

Source: classification engine

Classification label: mal68.troj.linELF@0/0@2/0

Stealing of Sensitive Information

Yara detected ConnectBack

Source: Yara match	File source: 5544x64.elf, type: SAMPLE
Source: Yara match	File source: 5486.1.0000000000400000.0000000000401000.rwx.sdmp, type: MEMORY

Remote Access Functionality

Yara detected ConnectBack

Source: Yara match	File source: 5544x64.elf, type: SAMPLE
Source: Yara match	File source: 5486.1.0000000000400000.0000000000401000.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	Direct Volume Access	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 Non-Application Layer Protocol	Automated Exfiltration	Data Encrypted for Impact
Employee Names	Virtual Private Server	Local Accounts	Cron	Login Hook	Login Hook	Binary Padding	NTDS	System Network Configuration Discovery	Distributed Component Object Model	Input Capture	2 Application Layer Protocol	Traffic Duplication	Data Destruction

Malware Configuration

Threatname: ConnectBack

{"C2": "45.43.36.223:5544"}

Behavior Graph

Hide Legend

Legend:

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

Antivirus, Machine Learning and Genetic Malware Detection

Initial Sample

Source	Detection	Scanner	Label	Link
5544x64.elf	63%	ReversingLabs	Linux.Backdoor.ConnectBack
5544x64.elf	100%	Joe Sandbox ML

Dropped Files

⊘No Antivirus matches

Domains

⊘No Antivirus matches

URLs

⊘No Antivirus matches

Domains and IPs

Contacted Domains

Name	IP	Active	Malicious	Antivirus Detection	Reputation
daisy.ubuntu.com	162.213.35.25	true	false		high

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	Flag	ASN	ASN Name	Malicious
185.125.190.26	unknown	United Kingdom		41231	CANONICAL-ASGB	false
45.43.36.223	unknown	United States		135377	UHGL-AS-APUCloudHKHoldingsGroupLimitedHK	true

Joe Sandbox View / Context

IPs

Match	Associated Sample Name / URL	SHA 256	Detection	Threat Name	Link
185.125.190.26	zmap.x86.elf	Get hash	malicious	Okiru	Browse
	zmap.arm6.elf	Get hash	malicious	Mirai, Okiru	Browse
	main_arm.elf	Get hash	malicious	Mirai	Browse
	main_sh4.elf	Get hash	malicious	Mirai	Browse
	armv7l.elf	Get hash	malicious	Mirai	Browse
	armv6l.elf	Get hash	malicious	Mirai	Browse
	la.bot.sparc.elf	Get hash	malicious	Mirai	Browse
	main_x86_64.elf	Get hash	malicious	Mirai	Browse
	arc.elf	Get hash	malicious	Mirai	Browse
	sh4.elf	Get hash	malicious	Mirai	Browse
45.43.36.223	shell64.elf	Get hash	malicious	ConnectBack	Browse

Domains

Match	Associated Sample Name / URL	SHA 256	Detection	Threat Name	Link	Context
daisy.ubuntu.com	sh4.elf	Get hash	malicious	Mirai	Browse	162.213.35.24
	arm7.elf	Get hash	malicious	Mirai	Browse	162.213.35.24
	debug.dbg.elf	Get hash	malicious	Mirai, Okiru	Browse	162.213.35.25
	zmap.arm6.elf	Get hash	malicious	Mirai, Okiru	Browse	162.213.35.25
	mipsel.elf	Get hash	malicious	Gafgyt, Mirai	Browse	162.213.35.25
	x86_64.elf	Get hash	malicious	Gafgyt, Mirai	Browse	162.213.35.25
	powerpc.elf	Get hash	malicious	Gafgyt, Mirai	Browse	162.213.35.25
	armv7l.elf	Get hash	malicious	Gafgyt, Mirai	Browse	162.213.35.25
	8lSWx5kumf.elf	Get hash	malicious	Unknown	Browse	162.213.35.25
	UrVQpxwfbD.elf	Get hash	malicious	Unknown	Browse	162.213.35.24

ASNs

Match	Associated Sample Name / URL	SHA 256	Detection	Threat Name	Link	Context
CANONICAL-ASGB	ppc.elf	Get hash	malicious	Mirai	Browse	185.125.190.26
	zmap.mpsl.elf	Get hash	malicious	Mirai, Okiru	Browse	91.189.91.42
	mips.elf	Get hash	malicious	Mirai	Browse	91.189.91.42
	spc.elf	Get hash	malicious	Mirai	Browse	91.189.91.42
	zmap.ppc.elf	Get hash	malicious	Mirai, Okiru	Browse	91.189.91.42
	zmap.mips.elf	Get hash	malicious	Mirai, Okiru	Browse	91.189.91.42
	arm6.elf	Get hash	malicious	Mirai	Browse	91.189.91.42
	arm.elf	Get hash	malicious	Mirai	Browse	91.189.91.42
	m68k.elf	Get hash	malicious	Mirai	Browse	91.189.91.42
	x86.elf	Get hash	malicious	Mirai	Browse	91.189.91.42
UHGL-AS-APUCloudHKHoldingsGroupLimitedHK	rebirth.mpsl.elf	Get hash	malicious	Mirai, Okiru	Browse	128.1.49.123
	ORDER-401.exe	Get hash	malicious	FormBook	Browse	107.155.56.30
	MAERSK LINE SHIPPING DOC_4253.exe	Get hash	malicious	FormBook	Browse	107.155.56.30
	New Purchase Order.exe	Get hash	malicious	FormBook	Browse	107.155.56.30
	Docs.exe	Get hash	malicious	FormBook, PureLog Stealer	Browse	107.155.56.30
	nabppc.elf	Get hash	malicious	Unknown	Browse	107.155.48.54
	shell64.elf	Get hash	malicious	ConnectBack	Browse	45.43.36.223
	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

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:	5544x64.elf
File size:	250 bytes
MD5:	59683c48cdc2f63363942ca921f17af2
SHA1:	df29da5f5e3cbb7a8b34cd036cdedde8d6384b64
SHA256:	561b89228b562c0a0b53b5848a179fac10ae0226706db82e8dd24226da199d94
SHA512:	a830a894f1433ebff15721b9c974f744defdec688bf41634ae527e8a1f39932573c8f84780a954fd2d7154f3c45ef799ec457b0d21d91c4861ddd42f50fe1246
SSDEEP:	6:BnX//In8/r1uBxHocmTxteQ3RQdygg5XJYD:BvwncrAH3m9tn532D
TLSH:	8CD080330B0A40DADBE4033FA57859DCD77B8976574962311D90DC010C096046F52C75
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
Dec 16, 2024 17:59:49.397922993 CET	34390	5544	192.168.2.14	45.43.36.223
Dec 16, 2024 17:59:49.517844915 CET	5544	34390	45.43.36.223	192.168.2.14
Dec 16, 2024 17:59:49.518136024 CET	34390	5544	192.168.2.14	45.43.36.223
Dec 16, 2024 17:59:52.097798109 CET	5544	34390	45.43.36.223	192.168.2.14
Dec 16, 2024 17:59:52.100560904 CET	34390	5544	192.168.2.14	45.43.36.223
Dec 16, 2024 17:59:52.256668091 CET	34390	5544	192.168.2.14	45.43.36.223
Dec 16, 2024 17:59:52.376533985 CET	5544	34390	45.43.36.223	192.168.2.14
Dec 16, 2024 17:59:58.900115013 CET	46540	443	192.168.2.14	185.125.190.26
Dec 16, 2024 18:00:29.618916988 CET	46540	443	192.168.2.14	185.125.190.26

UDP Packets

Timestamp	Source Port	Dest Port	Source IP	Dest IP
Dec 16, 2024 17:59:52.865037918 CET	49269	53	192.168.2.14	1.1.1.1
Dec 16, 2024 17:59:52.865107059 CET	41193	53	192.168.2.14	1.1.1.1
Dec 16, 2024 17:59:53.087002993 CET	53	49269	1.1.1.1	192.168.2.14
Dec 16, 2024 17:59:53.095988989 CET	53	41193	1.1.1.1	192.168.2.14

DNS Queries

Timestamp	Source IP	Dest IP	Trans ID	OP Code	Name	Type	Class	DNS over HTTPS
Dec 16, 2024 17:59:52.865037918 CET	192.168.2.14	1.1.1.1	0xba81	Standard query (0)	daisy.ubuntu.com	A (IP address)	IN (0x0001)	false
Dec 16, 2024 17:59:52.865107059 CET	192.168.2.14	1.1.1.1	0xdf9f	Standard query (0)	daisy.ubuntu.com	28	IN (0x0001)	false

DNS Answers

Timestamp	Source IP	Dest IP	Trans ID	Reply Code	Name	CName	Address	Type	Class	DNS over HTTPS
Dec 16, 2024 17:59:53.087002993 CET	1.1.1.1	192.168.2.14	0xba81	No error (0)	daisy.ubuntu.com		162.213.35.25	A (IP address)	IN (0x0001)	false
Dec 16, 2024 17:59:53.087002993 CET	1.1.1.1	192.168.2.14	0xba81	No error (0)	daisy.ubuntu.com		162.213.35.24	A (IP address)	IN (0x0001)	false

System Behavior

Analysis Process: 5544x64.elf PID: 5486, Parent PID: 5409

General

Start time (UTC):	16:59:48
Start date (UTC):	16/12/2024
Path:	/tmp/5544x64.elf
Arguments:	/tmp/5544x64.elf
File size:	250 bytes
MD5 hash:	59683c48cdc2f63363942ca921f17af2

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 use an OSI non-application layer protocol for communication between host and C2 server or among infected hosts within a network. The list of possible protocols is extensive.Specific examples include use of network layer protocols, such as the Internet Control Message Protocol (ICMP), transport layer protocols, such as the User Datagram Protocol (UDP), session layer protocols, such as Socket Secure (SOCKS), as well as redirected/tunneled protocols, such as Serial over LAN (SOL).
Tactics:	Command and Control
Data Sources:	Network Traffic: Network Traffic Content, Network Traffic: Network Traffic Flow
Platforms:	Linux, macOS, Network, 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 5544x64.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

Stealing of Sensitive Information

Remote Access Functionality

Mitre Att&ck Matrix

Malware Configuration

Threatname: ConnectBack

Behavior Graph

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

UDP Packets

DNS Queries

DNS Answers

System Behavior

Analysis Process: 5544x64.elf PID: 5486, Parent PID: 5409

General

Chronological Activities

Linux Analysis Report
5544x64.elf