BobSoft Mini Delphi Packer

Created the Tuesday 21 June 2022. Updated 2 months ago.

The Delphi programming language can be an easy way to write applications and programs that leverage Windows API functions. In fact, some actors deliberately include the default libraries as a diversion to hamper static analysis and make the application "look legit" during dynamic analysis.

The packer goes to great lengths to ensure that it is not running in an analysis environment. Normal user activity involves many application windows being rotated or changed over a period of time. The first variant of the packer uses GetForegroundWindow API to check for the user activity of changing windows at least three times before it executes further. If it does not see the change of windows, it puts itself into an infinite sleep.

Technique Identifier

U1428

Technique Tags

delphi packer

Detection Rules

                                    rule PEiD_Bundle_v100_BoB_BobSoft: PEiD
{
    strings:
        $a = { 60 E8 21 02 00 00 8B 44 24 04 52 48 66 31 C0 66 81 38 4D 5A 75 F5 8B 50 3C 81 3C 02 50 45 00 00 75 E9 5A C2 04 00 60 89 DD 89 C3 8B 45 3C 8B 54 28 78 01 EA 52 8B 52 20 01 EA 31 C9 41 8B 34 8A }
    condition:
        $a at pe.entry_point

}
rule PluginToExe_v101_BoB_BobSoft_additional: PEiD
{
    strings:
        $a = { E8 00 00 00 00 29 C0 5D 81 ED C6 41 40 00 50 8F 85 71 40 40 00 50 FF 95 A5 41 40 00 89 85 6D 40 40 00 FF 95 A1 41 40 00 50 FF 95 B5 41 40 00 80 38 00 74 16 8A 08 80 F9 22 75 07 50 FF 95 B9 41 40 00 89 85 75 40 40 00 EB 6C 6A 01 8F 85 71 40 40 00 6A 58 6A }
    condition:
        $a at pe.entry_point

}
rule Upx_Lock_10_12_CyberDoom_Team_X_BoB_BobSoft: PEiD
{
    strings:
        $a = { 60 E8 00 00 00 00 5D 81 ED 48 12 40 00 60 E8 2B 03 00 00 61 }
    condition:
        $a at pe.entry_point

}
rule PEiD_Bundle_v102_v104_BoB_BobSoft: PEiD
{
    strings:
        $a = { 60 E8 ?? 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 36 ?? ?? ?? 2E ?? ?? ?? 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 80 00 00 00 00 4B 65 72 6E 65 6C 33 32 2E 44 }
    condition:
        $a at pe.entry_point

}
rule PEiD_Bundle_v100_BoB_BobSoft_additional: PEiD
{
    strings:
        $a = { 60 E8 21 02 00 00 8B 44 24 04 52 48 66 31 C0 66 81 38 4D 5A 75 F5 8B 50 3C 81 3C 02 50 45 00 00 75 E9 5A C2 04 00 60 89 DD 89 C3 8B 45 3C 8B 54 28 78 01 EA 52 8B 52 20 01 EA 31 C9 41 8B 34 8A }
    condition:
        $a at pe.entry_point

}
rule Splash_Bitmap_v100_With_Unpack_Code_BoB_Bobsoft: PEiD
{
    strings:
        $a = { E8 00 00 00 00 60 8B 6C 24 20 55 81 ED ?? ?? ?? ?? 8D BD ?? ?? ?? ?? 8D 8D ?? ?? ?? ?? 29 F9 31 C0 FC F3 AA 8B 04 24 48 66 25 00 F0 66 81 38 4D 5A 75 F4 8B 48 3C 81 3C 01 50 45 00 00 75 E8 89 85 ?? ?? ?? ?? 6A 40 }
    condition:
        $a at pe.entry_point

}
rule PEiD_Bundle_v100_v101_BoB_BobSoft_additional: PEiD
{
    strings:
        $a = { 60 E8 ?? 02 00 00 8B 44 24 04 52 48 66 31 C0 66 81 38 4D 5A 75 F5 8B 50 3C 81 3C 02 50 45 00 00 75 E9 5A C2 04 00 60 89 DD 89 C3 8B 45 3C 8B 54 28 78 01 EA 52 8B 52 20 01 EA 31 C9 41 8B 34 8A }
    condition:
        $a at pe.entry_point

}
rule PEiD_Bundle_V102_DLL_BoB_BobSoft: PEiD
{
    strings:
        $a = { 83 7C 24 08 01 0F 85 ?? ?? ?? ?? 60 E8 9C 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 41 00 08 00 39 00 08 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 80 00 00 00 }
    condition:
        $a at pe.entry_point

}
rule PluginToExe_v102_BoB_BobSoft: PEiD
{
    strings:
        $a = { E8 00 00 00 00 29 C0 5D 81 ED 32 42 40 00 50 8F 85 DD 40 40 00 50 FF 95 11 42 40 00 89 85 D9 40 40 00 FF 95 0D 42 40 00 50 FF 95 21 42 40 00 80 38 00 74 16 8A 08 80 F9 22 75 07 50 FF 95 25 42 40 00 89 85 E1 40 40 00 EB 6C 6A 01 8F 85 DD 40 40 00 6A 58 6A 40 FF 95 15 42 40 00 89 85 D5 40 40 00 89 C7 68 00 08 00 00 6A 40 FF 95 15 42 40 00 89 47 1C C7 07 58 00 }
        $b = { E8 00 00 00 00 29 C0 5D 81 ED 32 42 40 00 50 8F 85 DD 40 40 00 50 FF 95 11 42 40 00 89 85 D9 40 40 00 FF 95 0D 42 40 00 50 FF 95 21 42 40 00 80 38 00 74 16 8A 08 80 F9 22 75 07 50 FF 95 25 42 40 00 89 85 E1 40 40 00 EB 6C 6A 01 8F 85 DD 40 40 00 6A 58 6A }
    condition:
        for any of ($*) : ( $ at pe.entry_point )

}
rule PEiD_Bundle_v102_BoB_BobSoft: PEiD
{
    strings:
        $a = { 60 E8 9C 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 36 ?? ?? ?? 2E ?? ?? ?? 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 80 00 00 00 00 4B 65 72 6E 65 6C 33 32 2E 44 }
    condition:
        $a at pe.entry_point

}
rule PEiD_Bundle_v104_BoB_BobSoft: PEiD
{
    strings:
        $a = { 60 E8 A0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 36 ?? ?? ?? 2E ?? ?? ?? 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 80 00 00 00 00 4B 65 72 6E 65 6C 33 32 2E 44 }
    condition:
        $a at pe.entry_point

}
rule PEiD_Bundle_V101_BoB_BobSoft: PEiD
{
    strings:
        $a = { 60 E8 23 02 00 00 8B 44 24 04 52 48 66 31 C0 66 81 38 4D 5A 75 F5 8B 50 3C 81 3C 02 50 45 00 00 75 E9 5A C2 04 00 60 89 DD 89 C3 8B 45 3C 8B 54 28 78 01 EA 52 8B 52 20 01 EA 31 C9 41 8B 34 8A }
    condition:
        $a at pe.entry_point

}
rule PEiD_Bundle_102_DLL_BoB_BobSoft: PEiD
{
    strings:
        $a = { 83 7C 24 08 01 0F 85 ?? ?? ?? ?? 60 E8 9C 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 41 00 08 00 39 00 08 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 80 00 00 00 }
    condition:
        $a at pe.entry_point

}
rule Imploder_v104_BoB_BobSoft: PEiD
{
    strings:
        $a = { 60 E8 A0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 36 ?? ?? ?? 2E ?? ?? ?? 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 80 00 00 00 00 4B 65 72 6E 65 6C 33 32 2E 44 }
    condition:
        $a at pe.entry_point

}
rule PEiD_Bundle_v101_BoB_BobSoft_additional: PEiD
{
    strings:
        $a = { 60 E8 23 02 00 00 8B 44 24 04 52 48 66 31 C0 66 81 38 4D 5A 75 F5 8B 50 3C 81 3C 02 50 45 00 00 75 E9 5A C2 04 00 60 89 DD 89 C3 8B 45 3C 8B 54 28 78 01 EA 52 8B 52 20 01 EA 31 C9 41 8B 34 8A }
    condition:
        $a at pe.entry_point

}
rule PEiD_Bundle_V100_BoB_BobSoft: PEiD
{
    strings:
        $a = { 60 E8 21 02 00 00 8B 44 24 04 52 48 66 31 C0 66 81 38 4D 5A 75 F5 8B 50 3C 81 3C 02 50 45 00 00 75 E9 5A C2 04 00 60 89 DD 89 C3 8B 45 3C 8B 54 28 78 01 EA 52 8B 52 20 01 EA 31 C9 41 8B 34 8A }
    condition:
        $a at pe.entry_point

}
rule PEiD_Bundle_V102_BoB_BobSoft: PEiD
{
    strings:
        $a = { 60 E8 9C 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 36 ?? ?? ?? 2E ?? ?? ?? 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 80 00 00 00 00 4B 65 72 6E 65 6C 33 32 2E 44 }
    condition:
        $a at pe.entry_point

}
rule PluginToExe_v101_BoB_BobSoft: PEiD
{
    strings:
        $a = { E8 00 00 00 00 29 C0 5D 81 ED C6 41 40 00 50 8F 85 71 40 40 00 50 FF 95 A5 41 40 00 89 85 6D 40 40 00 FF 95 A1 41 40 00 50 FF 95 B5 41 40 00 80 38 00 74 16 8A 08 80 F9 22 75 07 50 FF 95 B9 41 40 00 89 85 75 40 40 00 EB 6C 6A 01 8F 85 71 40 40 00 6A 58 6A 40 FF 95 A9 41 40 00 89 85 69 40 40 00 89 C7 68 00 08 00 00 6A 40 FF 95 A9 41 40 00 89 47 1C C7 07 58 00 00 00 C7 47 20 00 08 00 00 C7 47 18 01 00 00 00 C7 47 34 04 10 88 00 8D 8D B9 40 40 00 89 4F 0C 8D 8D DB 40 40 00 89 4F 30 FF B5 69 40 40 00 FF 95 95 41 40 00 FF 77 1C 8F 85 75 40 40 00 8B 9D 6D 40 40 00 60 6A 00 6A 01 53 81 C3 ?? ?? ?? 00 FF D3 61 6A 00 68 44 69 45 50 FF B5 75 40 40 00 6A 00 81 C3 ?? ?? 00 00 FF D3 83 C4 10 83 BD 71 40 40 00 00 74 10 FF 77 1C FF 95 AD 41 40 00 57 FF 95 AD 41 40 00 6A 00 FF 95 9D 41 40 00 }
        $b = { E8 00 00 00 00 29 C0 5D 81 ED C6 41 40 00 50 8F 85 71 40 40 00 50 FF 95 A5 41 40 00 89 85 6D 40 40 00 FF 95 A1 41 40 00 50 FF 95 B5 41 40 00 80 38 00 74 16 8A 08 80 F9 22 75 07 50 FF 95 B9 41 40 00 89 85 75 40 40 00 EB 6C 6A 01 8F 85 71 40 40 00 6A 58 6A }
    condition:
        for any of ($*) : ( $ at pe.entry_point )

}
rule BobPack_v100_BoB_BobSoft: PEiD
{
    strings:
        $a = { 60 E8 00 00 00 00 8B 0C 24 89 CD 83 E9 06 81 ED ?? ?? ?? ?? E8 3D 00 00 00 89 85 ?? ?? ?? ?? 89 C2 B8 5D 0A 00 00 8D 04 08 E8 E4 00 00 00 8B 70 04 01 D6 E8 76 00 00 00 E8 51 01 00 00 E8 01 01 }
    condition:
        $a at pe.entry_point

}
rule BobSoft_Mini_Delphi_BoB_BobSoft_additional: PEiD
{
    strings:
        $a = { 55 8B EC 83 C4 F0 B8 ?? ?? ?? ?? E8 }
    condition:
        $a at pe.entry_point

}
rule BobSoft_Mini_Delphi_BoB_BobSoft: PEiD
{
    strings:
        $a = { 55 8B EC 83 C4 F0 53 56 B8 ?? ?? ?? ?? E8 ?? ?? ?? ?? 33 C0 55 68 ?? ?? ?? ?? 64 FF 30 64 89 20 B8 }
    condition:
        $a at pe.entry_point

}
rule PEiD_Bundle_v100_v101_BoB_BobSoft: PEiD
{
    strings:
        $a = { 60 E8 ?? 02 00 00 8B 44 24 04 52 48 66 31 C0 66 81 38 4D 5A 75 F5 8B 50 3C 81 3C 02 50 45 00 00 75 E9 5A C2 04 00 60 89 DD 89 C3 8B 45 3C 8B 54 28 78 01 EA 52 8B 52 20 01 EA 31 C9 41 8B 34 8A }
    condition:
        $a at pe.entry_point

}
rule BobPack_v100_BoB_BobSoft_additional: PEiD
{
    strings:
        $a = { 60 E8 00 00 00 00 8B 0C 24 89 CD 83 E9 06 81 ED ?? ?? ?? ?? E8 3D 00 00 00 89 85 ?? ?? ?? ?? 89 C2 B8 5D 0A 00 00 8D 04 08 E8 E4 00 00 00 8B 70 04 01 D6 E8 76 00 00 00 E8 51 01 00 00 E8 01 01 }
    condition:
        $a at pe.entry_point

}
rule PluginToExe_v102_BoB_BobSoft_additional: PEiD
{
    strings:
        $a = { E8 00 00 00 00 29 C0 5D 81 ED 32 42 40 00 50 8F 85 DD 40 40 00 50 FF 95 11 42 40 00 89 85 D9 40 40 00 FF 95 0D 42 40 00 50 FF 95 21 42 40 00 80 38 00 74 16 8A 08 80 F9 22 75 07 50 FF 95 25 42 40 00 89 85 E1 40 40 00 EB 6C 6A 01 8F 85 DD 40 40 00 6A 58 6A }
    condition:
        $a at pe.entry_point

}
rule PEiD_Bundle_v101_BoB_BobSoft: PEiD
{
    strings:
        $a = { 60 E8 23 02 00 00 8B 44 24 04 52 48 66 31 C0 66 81 38 4D 5A 75 F5 8B 50 3C 81 3C 02 50 45 00 00 75 E9 5A C2 04 00 60 89 DD 89 C3 8B 45 3C 8B 54 28 78 01 EA 52 8B 52 20 01 EA 31 C9 41 8B 34 8A }
    condition:
        $a at pe.entry_point

}
rule Splash_Bitmap_v100_BoB_Bobsoft: PEiD
{
    strings:
        $a = { E8 00 00 00 00 60 8B 6C 24 20 55 81 ED ?? ?? ?? ?? 8D BD ?? ?? ?? ?? 8D 8D ?? ?? ?? ?? 29 F9 31 C0 FC F3 AA 8B 04 24 48 66 25 00 F0 66 81 38 4D 5A 75 F4 8B 48 3C 81 3C 01 50 45 00 00 75 E8 89 85 ?? ?? ?? ?? 8D BD ?? ?? ?? ?? 6A 00 }
    condition:
        $a at pe.entry_point

}
rule Upx_Lock_10_12_CyberDoom_Team_X_BoB_BobSoft_additional: PEiD
{
    strings:
        $a = { 60 E8 00 00 00 00 5D 81 ED 48 12 40 00 60 E8 2B 03 00 00 61 }
    condition:
        $a at pe.entry_point

}
rule PluginToExe_v100_BoB_BobSoft_additional: PEiD
{
    strings:
        $a = { E8 00 00 00 00 29 C0 5D 81 ED D1 40 40 00 50 FF 95 B8 40 40 00 89 85 09 40 40 00 FF 95 B4 40 40 00 89 85 11 40 40 00 50 FF 95 C0 40 40 00 8A 08 80 F9 22 75 07 50 FF 95 C4 40 40 00 89 85 0D 40 40 00 8B 9D 09 40 40 00 60 6A 00 6A 01 53 81 C3 ?? ?? ?? 00 FF }
    condition:
        $a at pe.entry_point

}
rule PEiD_Bundle_v102_v103_DLL_BoB_BobSoft: PEiD
{
    strings:
        $a = { 83 7C 24 08 01 0F 85 ?? ?? ?? ?? 60 E8 9C 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 41 00 08 00 39 00 08 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 80 00 00 00 }
    condition:
        $a at pe.entry_point

}
rule PluginToExe_v100_BoB_BobSoft: PEiD
{
    strings:
        $a = { E8 00 00 00 00 29 C0 5D 81 ED D1 40 40 00 50 FF 95 B8 40 40 00 89 85 09 40 40 00 FF 95 B4 40 40 00 89 85 11 40 40 00 50 FF 95 C0 40 40 00 8A 08 80 F9 22 75 07 50 FF 95 C4 40 40 00 89 85 0D 40 40 00 8B 9D 09 40 40 00 60 6A 00 6A 01 53 81 C3 ?? ?? ?? 00 FF D3 61 6A 00 68 44 69 45 50 FF B5 0D 40 40 00 6A 00 81 C3 ?? ?? ?? 00 FF D3 83 C4 10 FF 95 B0 40 40 00 }
        $b = { E8 00 00 00 00 29 C0 5D 81 ED D1 40 40 00 50 FF 95 B8 40 40 00 89 85 09 40 40 00 FF 95 B4 40 40 00 89 85 11 40 40 00 50 FF 95 C0 40 40 00 8A 08 80 F9 22 75 07 50 FF 95 C4 40 40 00 89 85 0D 40 40 00 8B 9D 09 40 40 00 60 6A 00 6A 01 53 81 C3 ?? ?? ?? 00 FF }
    condition:
        for any of ($*) : ( $ at pe.entry_point )

}
rule PEiD_Bundle_v102_v103_BoB_BobSoft: PEiD
{
    strings:
        $a = { 60 E8 9C 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 36 ?? ?? ?? 2E ?? ?? ?? 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00 80 00 00 00 00 4B 65 72 6E 65 6C 33 32 2E 44 }
    condition:
        $a at pe.entry_point

}

Contributors

Thomas Roccia

Additional Resources

External Links

The resources provided below are associated links that will give you even more detailed information and research on current evasion technique. It is important to note that, while these resources may be helpful, it is important to exercise caution when following external links. As always, be careful when clicking on links from unknown sources, as they may lead to malicious content.

https://www.mandiant.com/resources/increased-use-of-delphi-packer-to-evade-malware-classification