SYMBOLCOMMON_NAMEaka. SYNONYMS
win.ragnarok (Back to overview)

Ragnarok


According to Bleeping Computer, the ransomware is used in targeted attacks against unpatched Citrix servers. It excludes Russian and Chinese targets using the system's Language ID for filtering. It also tries to disable Windows Defender and has a number of UNIX filepath references in its strings. Encryption method is AES using a dynamically generated key, then bundling this key up via RSA.

References
2022-06-23KasperskyNikita Nazarov, Vasily Davydov, Natalya Shornikova, Vladislav Burtsev, Danila Nasonov
@techreport{nazarov:20220623:hateful:bae0681, author = {Nikita Nazarov and Vasily Davydov and Natalya Shornikova and Vladislav Burtsev and Danila Nasonov}, title = {{The hateful eight: Kaspersky’s guide to modern ransomware groups’ TTPs}}, date = {2022-06-23}, institution = {Kaspersky}, url = {https://media.kasperskycontenthub.com/wp-content/uploads/sites/43/2022/06/23093553/Common-TTPs-of-the-modern-ransomware_low-res.pdf}, language = {English}, urldate = {2022-06-27} } The hateful eight: Kaspersky’s guide to modern ransomware groups’ TTPs
Conti Hive BlackByte BlackCat Clop LockBit Mespinoza Ragnarok
2022-03-17SophosTilly Travers
@online{travers:20220317:ransomware:df38f2f, author = {Tilly Travers}, title = {{The Ransomware Threat Intelligence Center}}, date = {2022-03-17}, organization = {Sophos}, url = {https://news.sophos.com/en-us/2022/03/17/the-ransomware-threat-intelligence-center/}, language = {English}, urldate = {2022-03-18} } The Ransomware Threat Intelligence Center
ATOMSILO Avaddon AvosLocker BlackKingdom Ransomware BlackMatter Conti Cring DarkSide dearcry Dharma Egregor Entropy Epsilon Red Gandcrab Karma LockBit LockFile Mailto Maze Nefilim RagnarLocker Ragnarok REvil RobinHood Ryuk SamSam Snatch WannaCryptor WastedLocker
2021-08-26Bleeping ComputerIonut Ilascu
@online{ilascu:20210826:ragnarok:71e3d60, author = {Ionut Ilascu}, title = {{Ragnarok ransomware releases master decryptor after shutdown}}, date = {2021-08-26}, organization = {Bleeping Computer}, url = {https://www.bleepingcomputer.com/news/security/ragnarok-ransomware-releases-master-decryptor-after-shutdown/}, language = {English}, urldate = {2021-08-31} } Ragnarok ransomware releases master decryptor after shutdown
Ragnarok
2021-05-10DarkTracerDarkTracer
@online{darktracer:20210510:intelligence:b9d1c3f, author = {DarkTracer}, title = {{Intelligence Report on Ransomware Gangs on the DarkWeb: List of victim organizations attacked by ransomware gangs released on the DarkWeb}}, date = {2021-05-10}, organization = {DarkTracer}, url = {https://docs.google.com/spreadsheets/d/1MI8Z2tBhmqQ5X8Wf_ozv3dVjz5sJOs-3}, language = {English}, urldate = {2021-05-13} } Intelligence Report on Ransomware Gangs on the DarkWeb: List of victim organizations attacked by ransomware gangs released on the DarkWeb
RansomEXX Avaddon Babuk Clop Conti Cuba DarkSide DoppelPaymer Egregor Hades LockBit Mailto Maze MedusaLocker Mespinoza Mount Locker Nefilim Nemty Pay2Key PwndLocker RagnarLocker Ragnarok RansomEXX REvil Sekhmet SunCrypt ThunderX
2021-02-23CrowdStrikeCrowdStrike
@techreport{crowdstrike:20210223:2021:bf5bc4f, author = {CrowdStrike}, title = {{2021 Global Threat Report}}, date = {2021-02-23}, institution = {CrowdStrike}, url = {https://go.crowdstrike.com/rs/281-OBQ-266/images/Report2021GTR.pdf}, language = {English}, urldate = {2021-02-25} } 2021 Global Threat Report
RansomEXX Amadey Anchor Avaddon BazarBackdoor Clop Cobalt Strike Conti Cutwail DanaBot DarkSide DoppelPaymer Dridex Egregor Emotet Hakbit IcedID JSOutProx KerrDown LockBit Mailto Maze MedusaLocker Mespinoza Mount Locker NedDnLoader Nemty Pay2Key PlugX Pushdo PwndLocker PyXie QakBot Quasar RAT RagnarLocker Ragnarok RansomEXX REvil Ryuk Sekhmet ShadowPad SmokeLoader Snake SUNBURST SunCrypt TEARDROP TrickBot WastedLocker Winnti Zloader KNOCKOUT SPIDER OUTLAW SPIDER RIDDLE SPIDER SOLAR SPIDER VIKING SPIDER
2020-05-21SophosSophosLabs Uncut
@online{uncut:20200521:asnark:e0bcbbc, author = {SophosLabs Uncut}, title = {{Asnarök attackers twice modified attack midstream}}, date = {2020-05-21}, organization = {Sophos}, url = {https://news.sophos.com/en-us/2020/05/21/asnarok2/}, language = {German}, urldate = {2021-05-04} } Asnarök attackers twice modified attack midstream
NOTROBIN Ragnarok
2020-01-28Bleeping ComputerLawrence Abrams
@online{abrams:20200128:ragnarok:713a314, author = {Lawrence Abrams}, title = {{Ragnarok Ransomware Targets Citrix ADC, Disables Windows Defender}}, date = {2020-01-28}, organization = {Bleeping Computer}, url = {https://www.bleepingcomputer.com/news/security/ragnarok-ransomware-targets-citrix-adc-disables-windows-defender/}, language = {English}, urldate = {2020-01-28} } Ragnarok Ransomware Targets Citrix ADC, Disables Windows Defender
Ragnarok
2020-01-25Github (k-vitali)Vitali Kremez
@online{kremez:20200125:extracted:3eb7aef, author = {Vitali Kremez}, title = {{Extracted Config for Ragnarok Ransomware}}, date = {2020-01-25}, organization = {Github (k-vitali)}, url = {https://github.com/k-vitali/Malware-Misc-RE/blob/master/2020-01-26-ragnarok-cfg-vk.notes.raw}, language = {English}, urldate = {2020-01-28} } Extracted Config for Ragnarok Ransomware
Ragnarok
Yara Rules
[TLP:WHITE] win_ragnarok_auto (20230125 | Detects win.ragnarok.)
rule win_ragnarok_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2023-01-25"
        version = "1"
        description = "Detects win.ragnarok."
        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/win.ragnarok"
        malpedia_rule_date = "20230124"
        malpedia_hash = "2ee0eebba83dce3d019a90519f2f972c0fcf9686"
        malpedia_version = "20230125"
        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 = { 8b7d28 33db c1fa06 6bc838 881f 8b049528754300 }
            // n = 6, score = 200
            //   8b7d28               | mov                 edi, dword ptr [ebp + 0x28]
            //   33db                 | xor                 ebx, ebx
            //   c1fa06               | sar                 edx, 6
            //   6bc838               | imul                ecx, eax, 0x38
            //   881f                 | mov                 byte ptr [edi], bl
            //   8b049528754300       | mov                 eax, dword ptr [edx*4 + 0x437528]

        $sequence_1 = { 8bca c1e918 0fb689104b4300 33d9 8bca c1e910 0fb6c9 }
            // n = 7, score = 200
            //   8bca                 | mov                 ecx, edx
            //   c1e918               | shr                 ecx, 0x18
            //   0fb689104b4300       | movzx               ecx, byte ptr [ecx + 0x434b10]
            //   33d9                 | xor                 ebx, ecx
            //   8bca                 | mov                 ecx, edx
            //   c1e910               | shr                 ecx, 0x10
            //   0fb6c9               | movzx               ecx, cl

        $sequence_2 = { e8???????? 83c002 03c7 50 e8???????? 83c410 }
            // n = 6, score = 200
            //   e8????????           |                     
            //   83c002               | add                 eax, 2
            //   03c7                 | add                 eax, edi
            //   50                   | push                eax
            //   e8????????           |                     
            //   83c410               | add                 esp, 0x10

        $sequence_3 = { 335008 8b4d0c c1e910 8955ec 0fb6d1 0fb6cb 8b1c9510544300 }
            // n = 7, score = 200
            //   335008               | xor                 edx, dword ptr [eax + 8]
            //   8b4d0c               | mov                 ecx, dword ptr [ebp + 0xc]
            //   c1e910               | shr                 ecx, 0x10
            //   8955ec               | mov                 dword ptr [ebp - 0x14], edx
            //   0fb6d1               | movzx               edx, cl
            //   0fb6cb               | movzx               ecx, bl
            //   8b1c9510544300       | mov                 ebx, dword ptr [edx*4 + 0x435410]

        $sequence_4 = { 8d5701 8a4f01 47 84c9 }
            // n = 4, score = 200
            //   8d5701               | lea                 edx, [edi + 1]
            //   8a4f01               | mov                 cl, byte ptr [edi + 1]
            //   47                   | inc                 edi
            //   84c9                 | test                cl, cl

        $sequence_5 = { 234da8 03c2 894598 8b45b8 2345b4 0bc8 c145a80a }
            // n = 7, score = 200
            //   234da8               | and                 ecx, dword ptr [ebp - 0x58]
            //   03c2                 | add                 eax, edx
            //   894598               | mov                 dword ptr [ebp - 0x68], eax
            //   8b45b8               | mov                 eax, dword ptr [ebp - 0x48]
            //   2345b4               | and                 eax, dword ptr [ebp - 0x4c]
            //   0bc8                 | or                  ecx, eax
            //   c145a80a             | rol                 dword ptr [ebp - 0x58], 0xa

        $sequence_6 = { 8bca c1e908 0fb6c9 c1e308 0fb689104b4300 33d9 0fb6ca }
            // n = 7, score = 200
            //   8bca                 | mov                 ecx, edx
            //   c1e908               | shr                 ecx, 8
            //   0fb6c9               | movzx               ecx, cl
            //   c1e308               | shl                 ebx, 8
            //   0fb689104b4300       | movzx               ecx, byte ptr [ecx + 0x434b10]
            //   33d9                 | xor                 ebx, ecx
            //   0fb6ca               | movzx               ecx, dl

        $sequence_7 = { c1651008 c1e908 0fb6c9 0fb689104b4300 314d10 8b4d10 334dec }
            // n = 7, score = 200
            //   c1651008             | shl                 dword ptr [ebp + 0x10], 8
            //   c1e908               | shr                 ecx, 8
            //   0fb6c9               | movzx               ecx, cl
            //   0fb689104b4300       | movzx               ecx, byte ptr [ecx + 0x434b10]
            //   314d10               | xor                 dword ptr [ebp + 0x10], ecx
            //   8b4d10               | mov                 ecx, dword ptr [ebp + 0x10]
            //   334dec               | xor                 ecx, dword ptr [ebp - 0x14]

        $sequence_8 = { 03b090c14200 03b40514ffffff 03f7 8bbde4feffff 01b5ecfeffff 8bd7 }
            // n = 6, score = 200
            //   03b090c14200         | add                 esi, dword ptr [eax + 0x42c190]
            //   03b40514ffffff       | add                 esi, dword ptr [ebp + eax - 0xec]
            //   03f7                 | add                 esi, edi
            //   8bbde4feffff         | mov                 edi, dword ptr [ebp - 0x11c]
            //   01b5ecfeffff         | add                 dword ptr [ebp - 0x114], esi
            //   8bd7                 | mov                 edx, edi

        $sequence_9 = { 8b4df4 0fb6c9 33148d105d4300 8bcb 335010 c1e910 8955f8 }
            // n = 7, score = 200
            //   8b4df4               | mov                 ecx, dword ptr [ebp - 0xc]
            //   0fb6c9               | movzx               ecx, cl
            //   33148d105d4300       | xor                 edx, dword ptr [ecx*4 + 0x435d10]
            //   8bcb                 | mov                 ecx, ebx
            //   335010               | xor                 edx, dword ptr [eax + 0x10]
            //   c1e910               | shr                 ecx, 0x10
            //   8955f8               | mov                 dword ptr [ebp - 8], edx

    condition:
        7 of them and filesize < 483328
}
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