Case op36 ·
evaluated model Qwen359B ·
judges ClaudeAI, GeminiAI, OpenAI
Selection reason: disagreement_census
Understanding point
matching flag with hard-coded values
Code snippet · op36/code1.txt
const char *__fastcall sub_14003154C(int a1)
{
int v1; // ecx
const char *result; // rax
int v3; // edx
int i; // esi
int v5; // edi
v1 = -1553087205;
result = 0x911E4FAALL;
if ( ((dword_1400D3BCC * (dword_1400D3BCC + 1)) & 1) != 0 && dword_1400D3BC8 >= 10 )
v1 = 0x911E4FAA;
v3 = 0xFA8AE2C6;
if ( ((dword_1400D3BCC * (dword_1400D3BCC + 1)) & 1) != 0 && dword_1400D3BC8 >= 10 )
v3 = 0x911E4FAA;
for ( i = 0x4A78CB0A; ; i = 0xFD03863D )
{
while ( 1 )
{
while ( 1 )
{
while ( 1 )
{
v5 = i;
if ( i > 0xFD03863C )
break;
if ( i > 0xB3F2457D )
{
if ( i == 0xB3F2457E )
{
i = 0xFD03863D;
result = "Sync Extension Settings";
}
else
{
i = v3;
if ( v5 != 0xFA3CFA5F )
{
i = v5;
if ( v5 == 0xFA8AE2C6 )
{
result = "Local Extension Settings";
i = v1;
}
}
}
}
else if ( i == 2204886279 )
{
i = 0x48644D35;
if ( a1 != 2 )
LABEL_31:
i = 0x7CA42685;
}
else if ( i == 0x911E4FAA )
{
i = 0xFA8AE2C6;
result = "Local Extension Settings";
}
else
{
i = 0xFD03863D;
}
}
if ( i <= 0x4A78CB09 )
break;
if ( i == 0x7CA42685 )
{
i = 0xFD03863D;
result = "Unknown Storage";
}
else if ( i == 0x7104BAB6 )
{
i = 0xB3F2457E;
if ( a1 >= 2 )
i = 0x836BE507;
}
else
{
i = 0x1B45F460;
if ( a1 > 0 )
i = 0x7104BAB6;
}
}
if ( i != 0x1B45F460 )
break;
i = 0xFA3CFA5F;
if ( a1 )
goto LABEL_31;
}
if ( i != 0x48644D35 )
break;
result = "IndexedDB";
}
return result;
}
Evaluated model output (what the LLM said about the code) · op36/result_Qwen359B1.txt
### 1. Functionality Description
The function `sub_14003154C` acts as a **lookup table disguised as a complex state machine**. It accepts an integer argument (`a1`) and returns a pointer to a specific string literal. The logic determines which string to return based on the value of `a1`, the value of a global variable (`dword_1400D3BCC`), and a sequence of internal integer states (`i`).
The returned strings are specific to **Google Chrome/Chromium browser internals**:
* `"Sync Extension Settings"`
* `"Local Extension Settings"`
* `"IndexedDB"`
* `"Unknown Storage"`
This indicates the malware is likely interacting with the browser's storage APIs or extension management system, potentially to register itself as a malicious extension, hide its persistence mechanism within the browser profile, or exfiltrate data via browser storage.
### 2. Well-Known Algorithms
* **Control Flow Flattening (Obfuscation):** The code does not use a standard `switch` or `if-else` statement. Instead, it uses a `for` loop with nested `while` loops and integer jumps (`i = 0x...`) to simulate a state machine. This is a common obfuscation technique to hinder static analysis.
* **Finite State Machine (FSM):** The logic follows a deterministic path through integer states (`i`) to reach a specific output string.
### 3. Indicators of Compromise (IOCs)
* **Strings (High Confidence):**
* `"Sync Extension Settings"`
* `"Local Extension Settings"`
* `"IndexedDB"`
* `"Unknown Storage"`
* **Magic Numbers (Binary Signatures):**
* `0x911E4FAA` (Associated with "Local Extension Settings")
* `0x48644D35` (Associated with "IndexedDB")
* `0xB3F2457E` (Associated with "Sync Extension Settings")
* `0x7CA42685` (Associated with "Unknown Storage")
* `0x4A78CB0A` (Initial loop state)
* `0x1B45F460` (Break condition for inner loop)
* **Global Variables:**
* `dword_1400D3BCC` (Used for parity check and threshold logic)
* `dword_1400D3BC8` (Used for threshold check `>= 10`)
### 4. MITRE ATT&CK Mapping
| Technique ID | Technique Name | Justification |
| :--- | :--- | :--- |
| **T1546.003** | **Browser Extensions** | The function returns strings specifically related to Chrome Extension settings (`"Local Extension Settings"`, `"Sync Extension Settings"`). This suggests the malware is attempting to register, manage, or hide within a browser extension to gain persistence or privileges. |
| **T1027** | **Obfuscated Files or Information** | The code uses control flow flattening (nested loops with integer jumps instead of standard branching) and magic numbers to hide the logic. This makes reverse engineering more difficult. |
| **T1564.003** | **Indicator of Compromise - Browser** | The function explicitly identifies browser storage artifacts (`"IndexedDB"`, `"Unknown Storage"`). This behavior is consistent with malware that leaves traces in the browser profile or uses the browser for data exfiltration. |
| **T1564.001** | **Indicator of Compromise - File System** | By referencing storage mechanisms like IndexedDB, the malware is interacting with the file system via the browser API to store data, which serves as an IOC for forensic analysis. |
### 5. Obfuscation and Evasion Techniques
* **Control Flow Flattening:** The logic is hidden inside a `for` loop that iterates through integer states (`i`) rather than a readable `switch` statement. This increases the entropy of the code and makes it harder for analysts to quickly identify the logic branches.
* **Magic Numbers:** Instead of using named constants or string literals for logic flow, the code uses raw hexadecimal integers (e.g., `0x4A78CB0A`). This prevents simple pattern matching on the code structure.
* **Runtime State Dependency:** The function checks `dword_1400D3BCC` and `dword_1400D3BC8`. These values likely change at runtime (e.g., based on execution count or anti-debugging checks). If `dword_1400D3BCC` is odd and `dword_1400D3BC8 >= 10`, the initial values `v1` and `v3` change, altering the state machine's starting point. This suggests **Polymorphism** or **Anti-Analysis** behavior.
### 6. Observed Facts vs. Inferred Behavior
| Category | Content |
| :--- | :--- |
| **Observed Fact** | The function returns the string `"Local Extension Settings"` when the internal state `i` equals `0x911E4FAA`. |
| **Inferred Behavior** | The malware is targeting Google Chrome or Chromium-based browsers to persist as an extension. |
| **Observed Fact** | The code uses a `for` loop with nested `while` loops and integer assignments (`i = 0x...`) instead of a `switch` statement. |
| **Inferred Behavior** | The code is intentionally obfuscated to evade static analysis tools and reverse engineers. |
| **Observed Fact** | The logic depends on `dword_1400D3BCC` and `dword_1400D3BC8` for branching decisions. |
| **Inferred Behavior** | The malware may be polymorphic or includes anti-debugging checks that alter its behavior based on runtime environment variables. |
| **Observed Fact** | The function returns `"IndexedDB"`. |
| **Inferred Behavior** | The malware is likely using the browser's IndexedDB API to store configuration data or exfiltrate information. |
| **Observed Fact** | The function name is `sub_14003154C`. |
| **Inferred Behavior** | The original symbol name has been stripped or renamed, indicating the binary is packed, stripped, or obfuscated. |
### Summary
This code snippet is a **browser-specific lookup function** heavily obfuscated. It is almost certainly part of a **Chrome Extension Dropper** or **Browser Hijacker**. The malware uses this function to determine which browser storage mechanism to utilize for persistence or data handling. The use of "Extension Settings" strings is a strong indicator of **T1546.003 (Browser Extensions)** persistence.
{
"understanding_point": "matching flag with hard-coded values",
"full_evaluation": "The understanding point concerns the function matching a flag or input value against hard-coded constants. The summary describes the function as a lookup table that determines which string to return based on the value of a1, a global variable, and internal integer states. Crucially, the summary repeatedly states that the function compares/matches internal states against specific hard-coded hexadecimal magic numbers: 0x911E4FAA (Local Extension Settings), 0x48644D35 (IndexedDB), 0xB3F2457E (Sync Extension Settings), 0x7CA42685 (Unknown Storage). It explicitly states, for example, 'The function returns the string \"Local Extension Settings\" when the internal state i equals 0x911E4FAA.' This directly conveys the idea of matching a value against hard-coded constants. The summary clearly describes matching against these hard-coded values to select a result, which is exactly the understanding point.",
"explanation": "The summary clearly describes the function matching internal state/flag values against hard-coded hexadecimal constants (e.g., returns a string when state equals 0x911E4FAA), which directly conveys the understanding point.",
"evidence": "The function returns the string \"Local Extension Settings\" when the internal state `i` equals `0x911E4FAA`.",
"support_strength": 3,
"satisfied": "true"
}
{
"understanding_point": "matching flag with hard-coded values",
"full_evaluation": "The summary explicitly states that the function's logic determines which string to return based on an integer argument (`a1`), a global variable (`dword_1400D3BCC`), and internal integer states (`i`). It then lists several \"Magic Numbers\" (e.g., `0x911E4FAA`, `0x48644D35`) and associates them with specific output strings. Crucially, it provides an \"Observed Fact\" stating: \"The function returns the string \\\"Local Extension Settings\\\" when the internal state `i` equals `0x911E4FAA`.\" Here, `i` acts as a flag (internal state) that is matched against the hard-coded value `0x911E4FAA`. The summary also notes that the code uses \"raw hexadecimal integers\" for logic flow instead of named constants, reinforcing the idea of hard-coded values being used for matching/branching decisions. This directly and clearly addresses the understanding point.",
"explanation": "The summary explicitly describes how internal states (`i`) are matched against specific hard-coded hexadecimal values (magic numbers) to determine the function's output, directly fulfilling the understanding point.",
"evidence": "The function returns the string \"Local Extension Settings\" when the internal state `i` equals `0x911E4FAA`.",
"support_strength": 3,
"satisfied": "true"
}
{
"understanding_point": "matching flag with hard-coded values",
"full_evaluation": "The candidate summary discusses hard-coded hexadecimal constants, calling them magic numbers, and describes the function as a lookup/state-machine that returns different strings based on integer values. It also gives an observed fact that an internal state equals a hard-coded value such as 0x911E4FAA. However, it does not clearly state that a flag is being matched against hard-coded values. The only matching described is for internal state variables or lookup logic, and the word or concept of a flag being compared to constants is not explicitly established. Therefore, the summary partially overlaps with the idea of hard-coded value matching but omits the non-trivial element that the matched item is a flag.",
"explanation": "The summary mentions hard-coded magic numbers and equality checks involving internal state, but it does not clearly say that a flag is matched against those hard-coded values. This is related but incomplete relative to the understanding point.",
"evidence": "The function returns the string \"Local Extension Settings\" when the internal state `i` equals `0x911E4FAA`.",
"support_strength": 2,
"satisfied": "false"
}