rule elf_persirai_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2026-05-04"
        version = "1"
        description = "Detects elf.persirai."
        info = "autogenerated rule brought to you by yara-signator"
        tool = "yara-signator v0.6.0"
        signator_config = "callsandjumps;datarefs;binvalue"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/elf.persirai"
        malpedia_rule_date = "20260422"
        malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
        malpedia_version = "20260504"
        malpedia_license = "CC BY-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    /* DISCLAIMER
     * The strings used in this rule have been automatically selected from the
     * disassembly of memory dumps and unpacked files, using YARA-Signator.
     * The code and documentation is published here:
     * https://github.com/fxb-cocacoding/yara-signator
     * As Malpedia is used as data source, please note that for a given
     * number of families, only single samples are documented.
     * This likely impacts the degree of generalization these rules will offer.
     * Take the described generation method also into consideration when you
     * apply the rules in your use cases and assign them confidence levels.
     */


    strings:
        $sequence_0 = { 57 56 53 81ec0c280000 8bac2428280000 81bc2424280000ff270000 7779 }
            // n = 7, score = 100
            //   57                   | push                edi
            //   56                   | push                esi
            //   53                   | push                ebx
            //   81ec0c280000         | sub                 esp, 0x280c
            //   8bac2428280000       | mov                 ebp, dword ptr [esp + 0x2828]
            //   81bc2424280000ff270000     | cmp    dword ptr [esp + 0x2824], 0x27ff
            //   7779                 | ja                  0x7b

        $sequence_1 = { 31c0 81c4a4000000 5b 5e c3 89e2 }
            // n = 6, score = 100
            //   31c0                 | xor                 eax, eax
            //   81c4a4000000         | add                 esp, 0xa4
            //   5b                   | pop                 ebx
            //   5e                   | pop                 esi
            //   c3                   | ret                 
            //   89e2                 | mov                 edx, esp

        $sequence_2 = { 894108 c7411420000000 5b 5e c3 }
            // n = 5, score = 100
            //   894108               | mov                 dword ptr [ecx + 8], eax
            //   c7411420000000       | mov                 dword ptr [ecx + 0x14], 0x20
            //   5b                   | pop                 ebx
            //   5e                   | pop                 esi
            //   c3                   | ret                 

        $sequence_3 = { 57 56 53 83ec0c 89c7 be???????? }
            // n = 6, score = 100
            //   57                   | push                edi
            //   56                   | push                esi
            //   53                   | push                ebx
            //   83ec0c               | sub                 esp, 0xc
            //   89c7                 | mov                 edi, eax
            //   be????????           |                     

        $sequence_4 = { 53 e8???????? 66c744241c0200 83c410 eb16 66833b02 7410 }
            // n = 7, score = 100
            //   53                   | push                ebx
            //   e8????????           |                     
            //   66c744241c0200       | mov                 word ptr [esp + 0x1c], 2
            //   83c410               | add                 esp, 0x10
            //   eb16                 | jmp                 0x18
            //   66833b02             | cmp                 word ptr [ebx], 2
            //   7410                 | je                  0x12

        $sequence_5 = { 56 53 83ec0c 89c7 be???????? }
            // n = 5, score = 100
            //   56                   | push                esi
            //   53                   | push                ebx
            //   83ec0c               | sub                 esp, 0xc
            //   89c7                 | mov                 edi, eax
            //   be????????           |                     

        $sequence_6 = { 83ec10 8b5c2418 ff74241c 53 e8???????? 83c410 83caff }
            // n = 7, score = 100
            //   83ec10               | sub                 esp, 0x10
            //   8b5c2418             | mov                 ebx, dword ptr [esp + 0x18]
            //   ff74241c             | push                dword ptr [esp + 0x1c]
            //   53                   | push                ebx
            //   e8????????           |                     
            //   83c410               | add                 esp, 0x10
            //   83caff               | or                  edx, 0xffffffff

        $sequence_7 = { 89c3 8b8424b4000000 8944241c 8b8424b8000000 89442420 8b8424bc000000 89442424 }
            // n = 7, score = 100
            //   89c3                 | mov                 ebx, eax
            //   8b8424b4000000       | mov                 eax, dword ptr [esp + 0xb4]
            //   8944241c             | mov                 dword ptr [esp + 0x1c], eax
            //   8b8424b8000000       | mov                 eax, dword ptr [esp + 0xb8]
            //   89442420             | mov                 dword ptr [esp + 0x20], eax
            //   8b8424bc000000       | mov                 eax, dword ptr [esp + 0xbc]
            //   89442424             | mov                 dword ptr [esp + 0x24], eax

        $sequence_8 = { 8b542418 89d0 83c41c c3 56 53 83c8ff }
            // n = 7, score = 100
            //   8b542418             | mov                 edx, dword ptr [esp + 0x18]
            //   89d0                 | mov                 eax, edx
            //   83c41c               | add                 esp, 0x1c
            //   c3                   | ret                 
            //   56                   | push                esi
            //   53                   | push                ebx
            //   83c8ff               | or                  eax, 0xffffffff

        $sequence_9 = { d1fa 0fb68292810508 c3 55 57 56 53 }
            // n = 7, score = 100
            //   d1fa                 | sar                 edx, 1
            //   0fb68292810508       | movzx               eax, byte ptr [edx + 0x8058192]
            //   c3                   | ret                 
            //   55                   | push                ebp
            //   57                   | push                edi
            //   56                   | push                esi
            //   53                   | push                ebx

    condition:
        7 of them and filesize < 229376
}

rule elf_persirai_w0 {
    meta:
        description = "Detects Persirai Botnet Malware"
        soure = "http://blog.trendmicro.com/trendlabs-security-intelligence/persirai-new-internet-things-iot-botnet-targets-ip-cameras/"
        author = "Tim Yeh"
        reference = "Internal Research"
        date = "2017-04-21"
        hash = "f736948bb4575c10a3175f0078a2b5d36cce1aa4cd635307d03c826e305a7489"
        malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/elf.persirai"
        malpedia_version = "20170509"
        malpedia_license = "CC BY-NC-SA 4.0"
        malpedia_sharing = "TLP:WHITE"

    strings:
        $x1 = "ftpupload.sh" fullword ascii
        $x2 = "/dev/misc/watchdog" fullword ascii
        $x3 = "/dev/watchdog" ascii
        $x4 = ":52869/picsdesc.xml" fullword ascii
        $x5 = "npxXoudifFeEgGaACScs" fullword ascii

        $s1 = "ftptest.cgi" fullword ascii
        $s2 = "set_ftp.cgi" fullword ascii
        $s3 = "2580e538f3723927f1ea2fdb8d57b99e9cc37ced1" fullword ascii
        $s4 = "023ea8c671c0abf77241886465200cf81b1a2bf5e" fullword ascii

    condition:
        uint16(0) == 0x457f and filesize < 300KB and ((1 of ($x*) and 1 of ($s*)) or 2 of ($s*))
}