How are phone numbers used in surveillance software?

[suhashini25]

Phone numbers serve as a primary identifier and a critical hub for surveillance software, enabling various forms of monitoring, tracking, and data collection. Their ubiquitous use in digital identity and communication makes them an invaluable target for intelligence agencies, law enforcement, and, illicitly, private actors or malicious entities.

Here's how phone numbers are used in surveillance software:

1. As a Direct Identifier for Interception (Lawful Interception)
Targeting: The most direct use is to designate a phone number as a "target" for interception. Telecommunication providers, by legal mandate in many countries (e.g., through frameworks like CALEA in the US or similar laws in Bangladesh), are required to have "lawful interception" capabilities built into their networks.
Call Content Interception: Once a number is targeted, surveillance software connected to these lawful interception gateways can record the content of voice calls (both incoming and outgoing). This involves creating a copy of the audio stream and forwarding it to the authorized agency.
SMS/MMS Interception: Similarly, the content of text messages (SMS) and multimedia messages (MMS) sent to or from the target number can be intercepted and transmitted to the surveillance system.
Metadata Collection (IRI/CDR): Even without content interception, extensive facebook phone number list metadata related to the phone number's communication is collected. This includes the A-number (caller), B-number (recipient), timestamps of calls/messages, call duration, unique identifiers of devices involved, and sometimes the cell tower location at the start/end of a call. This data, known as Intercept Related Information (IRI) or Call Detail Records (CDRs), is a goldmine for intelligence.
2. For Location Tracking
Cell Tower Triangulation: Phone numbers are continuously connected to cellular networks. Surveillance software, often used by law enforcement with court orders, can leverage records from multiple cell towers that a phone connects to, triangulating or trilaterating its position over time. This provides historical and sometimes real-time location data, mapping an individual's movements.
GPS Data (via device exploitation): If surveillance software (e.g., spyware like Pegasus or commercial stalkerware) is directly installed on a target's phone (often through exploits or social engineering), it can directly access the device's GPS receiver, providing highly accurate, real-time location tracking that is far more precise than cell tower data.
3. As a Key to Digital Identity and Account Access
Account Takeover (ATO) / SIM Swaps: A phone number is often the primary identifier for numerous online services (email, banking, social media, messaging apps) and is frequently used for two-factor authentication (2FA) via SMS OTPs. Surveillance software, or techniques aided by intelligence gathered through phone number surveillance, can exploit this. For example, if a SIM swap is performed (transferring a number to a fraudster's SIM), the surveillance operation (or fraudsters) can then intercept OTPs and gain access to a multitude of online accounts associated with that number.
SMS Interception for OTPs: Even without a SIM swap, direct interception of SMS messages can allow surveillance software to capture one-time passwords (OTPs) or password reset links, enabling unauthorized access to accounts.
Contact Syncing: Spyware on a device can access and exfiltrate the entire contact list associated with that phone, including names, other numbers, and email addresses, thereby expanding the surveillance network.
4. For Network Analysis and Link Analysis
Social Graph Mapping: By analyzing who a target phone number communicates with (frequency, duration, reciprocity of calls/SMS), surveillance software (often employing graph neural networks or social network analysis algorithms) can map out an individual's entire social and professional network. This helps identify associates, key contacts, and even their roles within groups.
Pattern Recognition: Surveillance systems can identify patterns in communication that indicate specific behaviors, such as contacts only communicated with during business hours, contacts called only in emergencies, or communication with known criminal numbers.
Co-location Analysis: If location data is available, the system can identify other phone numbers that frequently co-locate with the target number, suggesting physical proximity and potential association.
5. Through Device-Resident Spyware/Stalkerware
Direct Access: Malicious software directly installed on a smartphone uses the phone number as the primary identifier to send captured data (call logs, SMS, GPS, microphone recordings, app usage, photos) to a remote server controlled by the surveillance operator. The number helps tag and organize the vast amounts of data collected from the compromised device.
Remote Control: The phone number can be used by the operator to send silent commands to the spyware on the device, instructing it to activate the microphone, turn on the camera, extract specific files, or send location updates.
The use of phone numbers in surveillance software underscores their critical role as digital identifiers and communication hubs. While legitimate law enforcement agencies operate under strict legal frameworks (requiring warrants, court orders, and oversight), the same capabilities can be, and often are, misused by state actors against dissidents, journalists, human rights activists, or by private individuals in cases of stalking or corporate espionage.