SYMBOLCOMMON_NAMEaka. SYNONYMS
win.avast_disabler (Back to overview)

AvastDisabler


There is no description at this point.

References
2017-01-04SecurityIntelligenceLior Keshet
@online{keshet:20170104:exposing:fd0938e, author = {Lior Keshet}, title = {{Exposing an AV-Disabling Driver Just in Time for Lunch}}, date = {2017-01-04}, organization = {SecurityIntelligence}, url = {https://securityintelligence.com/exposing-av-disabling-drivers-just-in-time-for-lunch/}, language = {English}, urldate = {2020-01-10} } Exposing an AV-Disabling Driver Just in Time for Lunch
AvastDisabler
Yara Rules
[TLP:WHITE] win_avast_disabler_auto (20220516 | Detects win.avast_disabler.)
rule win_avast_disabler_auto {

    meta:
        author = "Felix Bilstein - yara-signator at cocacoding dot com"
        date = "2022-05-16"
        version = "1"
        description = "Detects win.avast_disabler."
        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.avast_disabler"
        malpedia_rule_date = "20220513"
        malpedia_hash = "7f4b2229e6ae614d86d74917f6d5b41890e62a26"
        malpedia_version = "20220516"
        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 = { 8b85ecfeffff 33c9 0fb7d0 33c0 663bc2 7378 0fb7c1 }
            // n = 7, score = 100
            //   8b85ecfeffff         | mov                 eax, dword ptr [ebp - 0x114]
            //   33c9                 | xor                 ecx, ecx
            //   0fb7d0               | movzx               edx, ax
            //   33c0                 | xor                 eax, eax
            //   663bc2               | cmp                 ax, dx
            //   7378                 | jae                 0x7a
            //   0fb7c1               | movzx               eax, cx

        $sequence_1 = { 6a01 ff7508 bf???????? 57 }
            // n = 4, score = 100
            //   6a01                 | push                1
            //   ff7508               | push                dword ptr [ebp + 8]
            //   bf????????           |                     
            //   57                   | push                edi

        $sequence_2 = { 6bf80e 668b450c 6639443712 7408 }
            // n = 4, score = 100
            //   6bf80e               | imul                edi, eax, 0xe
            //   668b450c             | mov                 ax, word ptr [ebp + 0xc]
            //   6639443712           | cmp                 word ptr [edi + esi + 0x12], ax
            //   7408                 | je                  0xa

        $sequence_3 = { 50 ff15???????? ff7508 ff15???????? 5f }
            // n = 5, score = 100
            //   50                   | push                eax
            //   ff15????????         |                     
            //   ff7508               | push                dword ptr [ebp + 8]
            //   ff15????????         |                     
            //   5f                   | pop                 edi

        $sequence_4 = { 8d4508 897de0 50 c745e840020000 }
            // n = 4, score = 100
            //   8d4508               | lea                 eax, [ebp + 8]
            //   897de0               | mov                 dword ptr [ebp - 0x20], edi
            //   50                   | push                eax
            //   c745e840020000       | mov                 dword ptr [ebp - 0x18], 0x240

        $sequence_5 = { 51 51 a1???????? b94ee640bb }
            // n = 4, score = 100
            //   51                   | push                ecx
            //   51                   | push                ecx
            //   a1????????           |                     
            //   b94ee640bb           | mov                 ecx, 0xbb40e64e

        $sequence_6 = { 57 33db 6a08 0fb706 8d5602 8985ecfeffff 0fb7c0 }
            // n = 7, score = 100
            //   57                   | push                edi
            //   33db                 | xor                 ebx, ebx
            //   6a08                 | push                8
            //   0fb706               | movzx               eax, word ptr [esi]
            //   8d5602               | lea                 edx, [esi + 2]
            //   8985ecfeffff         | mov                 dword ptr [ebp - 0x114], eax
            //   0fb7c0               | movzx               eax, ax

        $sequence_7 = { 7520 c605????????01 33c9 8a8100304000 }
            // n = 4, score = 100
            //   7520                 | jne                 0x22
            //   c605????????01       |                     
            //   33c9                 | xor                 ecx, ecx
            //   8a8100304000         | mov                 al, byte ptr [ecx + 0x403000]

        $sequence_8 = { c745e840020000 897dec 897df0 ff15???????? 8bf0 85f6 783f }
            // n = 7, score = 100
            //   c745e840020000       | mov                 dword ptr [ebp - 0x18], 0x240
            //   897dec               | mov                 dword ptr [ebp - 0x14], edi
            //   897df0               | mov                 dword ptr [ebp - 0x10], edi
            //   ff15????????         |                     
            //   8bf0                 | mov                 esi, eax
            //   85f6                 | test                esi, esi
            //   783f                 | js                  0x41

        $sequence_9 = { 8b4508 6a01 c740345c114000 e8???????? 6a03 e8???????? }
            // n = 6, score = 100
            //   8b4508               | mov                 eax, dword ptr [ebp + 8]
            //   6a01                 | push                1
            //   c740345c114000       | mov                 dword ptr [eax + 0x34], 0x40115c
            //   e8????????           |                     
            //   6a03                 | push                3
            //   e8????????           |                     

    condition:
        7 of them and filesize < 41984
}
Download all Yara Rules