Functions

DISCLAIMER // NFA // DYOR

This analysis is based on observations of the contract behavior. We are not smart contract security experts. This document aims to explain what the contract appears to do based on the code. It should not be considered a comprehensive security audit or financial advice. Always verify critical information independently and consult with blockchain security professionals for important decisions.

⊙ generated by robots | curated by humans

METADATA
Contract Address	0xfD2487cc0e5dCe97F08BE1Bc8eF1DCE8D5988B4D (etherscan)
Network	Ethereum Mainnet
Analysis Date	2026-02-13

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Function Selectors

SELECTOR	FUNCTION SIGNATURE	CATEGORY
N/A	Doubler()	Constructor
N/A	fallback()	Payable Entry Point
0x13af4035	enter()	User
0x35c1d349	collectFees()	Admin
0x13af40ba	setOwner(address)	Admin

Summary

CATEGORY	NUM FUNCTIONS
Total Functions	5
User Functions	2 (enter, fallback)
Admin Functions	2 (collectFees, setOwner)
Constructor	1 (Doubler)
View Functions	0 (all state variables are public, auto-generated getters)

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Constructor

Function: Doubler()

OverviewKey ObservationsActionsState ChangesCode

Constructor function executed once at contract Deployment to initialize the contract owner.

ATTRIBUTE	VALUE
Selector	N/A (constructor)
Parameters	None
Access	Public (called once at deployment)
Payable	No

FLAG	OBSERVATION
☑	Simple owner initialization with no complex setup
☑	Owner cannot be zero address (would revert in later modifier checks)
△	No events emitted, making deployment tracking difficult

STEP	ACTION
1	Set owner to msg.sender (contract deployer)

VARIABLE	CHANGE
owner	Set to msg.sender (0x45ab6108cc41c20f416a98615aa8c349f02a275b)

function Doubler() {
    owner = msg.sender;
}

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User Functions

Function: fallback()

OverviewKey ObservationsActionsCode

Unnamed Fallback Function that executes when ETH is sent to the contract without function data. Delegates all calls to enter().

ATTRIBUTE	VALUE
Selector	N/A (fallback)
Parameters	None (accepts msg.value)
Access	Public, Payable

FLAG	OBSERVATION
☑	Simplifies UX - users can send ETH directly without function calls
△	No event emitted, making transaction tracking require full trace
☑	All logic delegated to enter(), maintaining single source of truth

STEP	ACTION
1	Call enter() function with current msg.value

function() {
    enter();
}

---

Function: enter()

OverviewKey ObservationsPreconditionsActionsState ChangesFailure CasesFlow DiagramCode

Primary entry point for participants to deposit ETH and join the Ponzi Scheme queue. Handles deposits, fee extraction, balance tracking, and automatic payouts when conditions are met.

ATTRIBUTE	VALUE
Selector	0x13af4035
Parameters	None (uses msg.value and msg.sender)
Access	Public, Payable

FLAG	OBSERVATION
△	Minimum deposit 1 ETH enforced, but refund uses send() which can fail silently
☒	First participant (idx=0) pays 100% in fees with no balance credit
△	send() for payouts can fail silently without reverting transaction
☒	balance variable can desync from actual contract balance due to failed sends
△	No event emitted for deposits, queue additions, or payouts
☒	Unbounded array growth - no limit on participants

CONDITION	REQUIREMENT
Minimum Deposit	msg.value >= 1 ether
Gas Available	Sufficient gas for array expansion and potential payout

STEP	ACTION
1	Check if msg.value < 1 ether - if true, refund via send() and return
2	Get current participants array length as idx
3	Expand participants array by 1
4	Store msg.sender as participants[idx].etherAddress
5	Store msg.value as participants[idx].amount
6	If idx != 0: Add msg.value / 10 to collectedFees and add msg.value to balance
7	Else (first participant): Add entire msg.value to collectedFees only
8	If balance > participants[payoutIdx].amount * 2: Calculate and send payout
9	Calculate transactionAmount = 2 * (participants[payoutIdx].amount - participants[payoutIdx].amount / 10)
10	Send transactionAmount to participants[payoutIdx].etherAddress via send()
11	Subtract participants[payoutIdx].amount * 2 from balance
12	Increment payoutIdx by 1

VARIABLE	CHANGE
participants[idx].etherAddress	Set to msg.sender
participants[idx].amount	Set to msg.value
participants.length	Incremented by 1
collectedFees	Increased by msg.value / 10 (or msg.value if first participant)
balance	Increased by msg.value (except first participant)
balance (on payout)	Decreased by participants[payoutIdx].amount * 2
payoutIdx (on payout)	Incremented by 1

CONDITION	REVERT MESSAGE
Deposit < 1 ETH	No revert - refund attempted via send()
Participant send() fails	No revert - △ silent failure, balance still decremented
Refund send() fails	No revert - △ silent failure, user loses funds
Out of gas	EVM revert (no custom message)

flowchart TD
    Start([enter called with msg.value]) --> CheckMin{msg.value >= 1 ETH?}

    CheckMin -->|No| Refund[send msg.value back to sender]
    Refund --> RefundSuccess{send successful?}
    RefundSuccess -->|Yes| End1([Return - deposit rejected])
    RefundSuccess -->|No| End2([△ Return - user lost ETH])

    CheckMin -->|Yes| GetIdx[idx = participants.length]
    GetIdx --> ExpandArray[participants.length += 1]
    ExpandArray --> StoreAddress[participants idx etherAddress = msg.sender]
    StoreAddress --> StoreAmount[participants idx amount = msg.value]

    StoreAmount --> IsFirst{idx == 0?}
    IsFirst -->|Yes| AllFees[collectedFees += msg.value]
    IsFirst -->|No| TenPercent[collectedFees += msg.value/10<br/>balance += msg.value]

    AllFees --> CheckPayout{balance > participants payoutIdx amount * 2?}
    TenPercent --> CheckPayout

    CheckPayout -->|No| End3([Transaction complete - waiting in queue])

    CheckPayout -->|Yes| CalcPayout[transactionAmount = 2 * amount - amount/10]
    CalcPayout --> SendPayout[send transactionAmount to participants payoutIdx]
    SendPayout --> PaySuccess{send successful?}

    PaySuccess -->|Yes| UpdateBalance[balance -= participants payoutIdx amount * 2]
    PaySuccess -->|No| UpdateBalanceAnyway[☒ balance -= amount * 2 ANYWAY]

    UpdateBalance --> IncrementIdx[payoutIdx += 1]
    UpdateBalanceAnyway --> IncrementIdx
    IncrementIdx --> End4([Transaction complete - payout sent])

    style RefundSuccess fill:#fff4cc
    style PaySuccess fill:#fff4cc
    style End2 fill:#ffcccc
    style UpdateBalanceAnyway fill:#ffcccc

function enter() {
    if (msg.value < 1 ether) {
        msg.sender.send(msg.value);
        return;
    }

    // add a new participant to array
    uint idx = participants.length;
    participants.length += 1;
    participants[idx].etherAddress = msg.sender;
    participants[idx].amount = msg.value;

    // collect fees and update contract balance
    if (idx != 0) {
        collectedFees += msg.value / 10;
        balance += msg.value;
    }
    else {
        // first participant has no one above him,
        // so it goes all to fees
        collectedFees += msg.value;
    }

// if there are enough ether on the balance we can pay out to an earlier participant
    if (balance > participants[payoutIdx].amount * 2) {
        uint transactionAmount = 2 * (participants[payoutIdx].amount - participants[payoutIdx].amount / 10);
        participants[payoutIdx].etherAddress.send(transactionAmount);

        balance -= participants[payoutIdx].amount * 2;
        payoutIdx += 1;
    }
}

---

Admin Functions

Function: collectFees()

OverviewKey ObservationsPreconditionsActionsState ChangesFailure CasesCode

Allows the contract owner to withdraw accumulated fees to their address. Fees represent 10% of all participant deposits.

ATTRIBUTE	VALUE
Selector	0x35c1d349
Parameters	None
Access	Owner only (via onlyowner modifier)
Payable	No

FLAG	OBSERVATION
☒	Owner can withdraw fees at any time without restrictions
△	Uses send() which can fail silently if owner is contract with fallback
△	If send fails, collectedFees is still set to 0 - permanent loss
△	No event emitted for fee collection
☑	Early exit if no fees to collect (gas optimization)

CONDITION	REQUIREMENT
Caller	Must be current owner address
Collected Fees	Must be greater than 0 (otherwise early return)

STEP	ACTION
1	Check if msg.sender == owner (via modifier)
2	If collectedFees == 0, return early
3	Send collectedFees amount to owner via send()
4	Set collectedFees = 0

VARIABLE	CHANGE
collectedFees	Set to 0
Owner ETH balance	Increased by collectedFees amount (if send succeeds)

CONDITION	REVERT MESSAGE
Caller is not owner	No revert - modifier prevents function body execution
send() to owner fails	No revert - △ collectedFees lost permanently
collectedFees == 0	No revert - early return

function collectFees() onlyowner {
    if (collectedFees == 0) return;

    owner.send(collectedFees);
    collectedFees = 0;
}

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Function: setOwner(address)

OverviewKey ObservationsPreconditionsActionsState ChangesFailure CasesCode

Allows the current owner to transfer ownership to a new address. No timelock or multi-step confirmation process.

ATTRIBUTE	VALUE
Selector	0x13af40ba
Parameters	address _owner - new owner address
Access	Owner only (via onlyowner modifier)
Payable	No

FLAG	OBSERVATION
☒	Ownership can be transferred instantly without delay
☒	No validation that _owner is not zero address
☒	Ownership could be transferred to contract that can't call functions
△	No event emitted for ownership transfer
☒	No two-step ownership transfer process

CONDITION	REQUIREMENT
Caller	Must be current owner address
New Owner	None - any address accepted (including 0x0)

STEP	ACTION
1	Check if msg.sender == owner (via modifier)
2	Set owner = _owner

VARIABLE	CHANGE
owner	Set to _owner parameter value

CONDITION	REVERT MESSAGE
Caller is not owner	No revert - modifier prevents function body execution

function setOwner(address _owner) onlyowner {
    owner = _owner;
}

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Access Control Modifier

Modifier: onlyowner

The onlyowner Modifier restricts function access to the contract owner. However, it uses deprecated Solidity syntax that doesn't explicitly Revert on failure.

Code:

modifier onlyowner { if (msg.sender == owner) _ }

Behavior:

• If msg.sender == owner: Execute function body (represented by _)
• Else: Do nothing (function body is not executed, but transaction succeeds with no revert)

Security Concern: In modern Solidity, this modifier would use require(msg.sender == owner, "Not owner"); to explicitly revert unauthorized calls. The deprecated syntax silently succeeds without executing the function, which could be confusing for callers expecting a revert.

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Public State Variables (Auto-Generated Getters)

While not explicit functions in the source code, Solidity automatically generates getter functions for all public State Variables:

FUNCTION	RETURN TYPE	PURPOSE
participants(uint256)	(address, uint256)	Returns etherAddress and amount for participant at given index
payoutIdx()	uint256	Returns current payout queue position (currently 118)
collectedFees()	uint256	Returns accumulated owner fees (currently 0)
balance()	uint256	Returns internal balance tracker (currently ~27.44 ETH)
owner()	address	Returns current owner address

These getters are callable by anyone and cost only gas for the RPC call (no transaction fee when called off-chain).