Linux Analysis Report
Rubify.arm.elf

Overview

General Information

Sample name: Rubify.arm.elf
Analysis ID: 1430811
MD5: 1b189f21c4dd58c832d08c70047a9023
SHA1: 4595ab350cdf9e98195728ac0419a6865efd1eef
SHA256: 032a7c24667344b89e73ac9ee57d6ac06d6eaaea3263beefc6f62cbe1941ecbe
Tags: elf
Infos:

Detection

Mirai
Score: 76
Range: 0 - 100
Whitelisted: false

Signatures

Malicious sample detected (through community Yara rule)
Multi AV Scanner detection for submitted file
Yara detected Mirai
Sample is packed with UPX
ELF contains segments with high entropy indicating compressed/encrypted content
Sample contains only a LOAD segment without any section mappings
Tries to connect to HTTP servers, but all servers are down (expired dropper behavior)
Uses the "uname" system call to query kernel version information (possible evasion)
Yara signature match

Classification

Name Description Attribution Blogpost URLs Link
Mirai Mirai is one of the first significant botnets targeting exposed networking devices running Linux. Found in August 2016 by MalwareMustDie, its name means "future" in Japanese. Nowadays it targets a wide range of networked embedded devices such as IP cameras, home routers (many vendors involved), and other IoT devices. Since the source code was published on "Hack Forums" many variants of the Mirai family appeared, infecting mostly home networks all around the world. No Attribution https://malpedia.caad.fkie.fraunhofer.de/details/elf.mirai

AV Detection
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Multi AV Scanner detection for submitted file
Source: Rubify.arm.elf Virustotal: Detection: 25% Perma Link
Source: Rubify.arm.elf ReversingLabs: Detection: 36%
Tries to connect to HTTP servers, but all servers are down (expired dropper behavior)
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: 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 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: Rubify.arm.elf, 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp String found in binary or memory: http://94.156.71.75/bin
Source: Rubify.arm.elf, 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp String found in binary or memory: http://94.156.71.75/bins/Rubify.mips;
Source: Rubify.arm.elf, 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp String found in binary or memory: http://94.156.71.75/bins/Rubify.x86
Source: Rubify.arm.elf, 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp String found in binary or memory: http://94.156.71.75/wget.sh;
Source: Rubify.arm.elf, 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp String found in binary or memory: http://schemas.xmlsoap.org/soap/encoding/
Source: Rubify.arm.elf, 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp String found in binary or memory: http://schemas.xmlsoap.org/soap/encoding//%22%3E
Source: Rubify.arm.elf, 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp String found in binary or memory: http://schemas.xmlsoap.org/soap/envelope/
Source: Rubify.arm.elf, 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp String found in binary or memory: http://schemas.xmlsoap.org/soap/envelope//
Source: Rubify.arm.elf String found in binary or memory: http://upx.sf.net
Source: unknown Network traffic detected: HTTP traffic on port 43928 -> 443
Source: unknown Network traffic detected: HTTP traffic on port 42836 -> 443

System Summary
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Malicious sample detected (through community Yara rule)
Source: 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp, type: MEMORY Matched rule: Linux_Trojan_Gafgyt_ea92cca8 Author: unknown
Source: 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp, type: MEMORY Matched rule: Detects ELF malware Mirai related Author: Florian Roth
Source: Process Memory Space: Rubify.arm.elf PID: 6224, type: MEMORYSTR Matched rule: Linux_Trojan_Gafgyt_ea92cca8 Author: unknown
Sample contains only a LOAD segment without any section mappings
Source: LOAD without section mappings Program segment: 0x8000
Yara signature match
Source: 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp, type: MEMORY Matched rule: Linux_Trojan_Gafgyt_ea92cca8 os = linux, severity = x86, creation_date = 2021-01-12, scan_context = file, memory, license = Elastic License v2, threat_name = Linux.Trojan.Gafgyt, fingerprint = aa4aee9f3d6bedd8234eaf8778895a0f5d71c42b21f2a428f01f121e85704e8e, id = ea92cca8-bba7-4a1c-9b88-a2d051ad0021, last_modified = 2021-09-16
Source: 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp, type: MEMORY Matched rule: MAL_ELF_LNX_Mirai_Oct10_2 date = 2018-10-27, hash1 = fa0018e75f503f9748a5de0d14d4358db234f65e28c31c8d5878cc58807081c9, author = Florian Roth, description = Detects ELF malware Mirai related, reference = Internal Research
Source: Process Memory Space: Rubify.arm.elf PID: 6224, type: MEMORYSTR Matched rule: Linux_Trojan_Gafgyt_ea92cca8 os = linux, severity = x86, creation_date = 2021-01-12, scan_context = file, memory, license = Elastic License v2, threat_name = Linux.Trojan.Gafgyt, fingerprint = aa4aee9f3d6bedd8234eaf8778895a0f5d71c42b21f2a428f01f121e85704e8e, id = ea92cca8-bba7-4a1c-9b88-a2d051ad0021, last_modified = 2021-09-16
Source: classification engine Classification label: mal76.troj.evad.linELF@0/0@0/0

Data Obfuscation
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Sample is packed with UPX
Source: initial sample String containing UPX found: $Info: This file is packed with the UPX executable packer http://upx.sf.net $
Source: initial sample String containing UPX found: $Info: This file is packed with the UPX executable packer http://upx.sf.net $
Source: initial sample String containing UPX found: $Id: UPX 3.94 Copyright (C) 1996-2017 the UPX Team. All Rights Reserved. $
ELF contains segments with high entropy indicating compressed/encrypted content
Source: Rubify.arm.elf Submission file: segment LOAD with 7.9605 entropy (max. 8.0)
Uses the "uname" system call to query kernel version information (possible evasion)
Source: /tmp/Rubify.arm.elf (PID: 6224) Queries kernel information via 'uname': Jump to behavior
Source: Rubify.arm.elf, 6224.1.00007ffdbf5bd000.00007ffdbf5de000.rw-.sdmp Binary or memory string: x86_64/usr/bin/qemu-arm/tmp/Rubify.arm.elfSUDO_USER=saturninoPATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/binDISPLAY=:1.0XAUTHORITY=/run/user/1000/gdm/XauthoritySUDO_UID=1000TERM=xterm-256colorCOLORTERM=truecolorLOGNAME=rootUSER=rootLANG=en_US.UTF-8SUDO_COMMAND=/bin/bashHOME=/rootMAIL=/var/mail/rootSUDO_GID=1000SHELL=/bin/bash/tmp/Rubify.arm.elf
Source: Rubify.arm.elf, 6224.1.000055aaacac8000.000055aaacc16000.rw-.sdmp Binary or memory string: U!/etc/qemu-binfmt/arm
Source: Rubify.arm.elf, 6224.1.000055aaacac8000.000055aaacc16000.rw-.sdmp Binary or memory string: /etc/qemu-binfmt/arm
Source: Rubify.arm.elf, 6224.1.00007ffdbf5bd000.00007ffdbf5de000.rw-.sdmp Binary or memory string: /usr/bin/qemu-arm
Source: Rubify.arm.elf, 6224.1.00007ffdbf5bd000.00007ffdbf5de000.rw-.sdmp Binary or memory string: qemu: uncaught target signal 11 (Segmentation fault) - core dumped

Stealing of Sensitive Information
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Yara detected Mirai
Source: Yara match File source: 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp, type: MEMORY

Remote Access Functionality
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Yara detected Mirai
Source: Yara match File source: 6224.1.00007f8a5c017000.00007f8a5c02d000.r-x.sdmp, type: MEMORY

No Screenshots

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

Contacted Public IPs

IP Domain Country Flag ASN ASN Name Malicious
109.202.202.202
 unknown Switzerland
13030 INIT7CH false
91.189.91.43
 unknown United Kingdom
41231 CANONICAL-ASGB false
91.189.91.42
 unknown United Kingdom
41231 CANONICAL-ASGB false