Steganography Attack
Steganography is the practice of concealing a file, message, image, video, or program within another file in such a way that someone can not know the presence or contents of the hidden message or file. Steganography is an encryption technique to protect data and can be used along with cryptography for extra protection. The purpose of steganography is covert communication to hide a message from a third party or to hide the contents of the hidden file from the recipient usually for malicious intent. Steganography Attack is a type of cyber attack that is carried out to evade system/human detection of a harmful program or secret message, this technique is also a common vehicle for secret communication other than or along with cryptography techniques for extra protection. Hackers use steganography techniques to embed and deliver malicious code such as viruses, adware, spyware, etc as well as malicious payloads. There are different ways the attacker hides the message or file to another file, this method is known as ‘free bytes and injection’. Free bytes in a file are not necessary and this byte can be replaced with a secret message or file. The second method is to inject a secret message or file into another file or image which increases the size of the original file or image.
The technique for detecting a steganographic file or image is known as Steganalysis, it can be used to decrypt for exposing the hidden files or messages from the original file. Malware can be delivered to a target system through steganography, when dealing with suspicious steganographic images or files, Steganalysis Tools can be used to analyze such files.
While steganography itself is not inherently malicious, it can be used in cyber attacks to hide malicious payloads or exfiltrate sensitive information.
Here are some types of steganography attacks:
- Image Steganography:
- Description: Concealing information within images by manipulating the pixel values. The changes are often imperceptible to the human eye.
- Use Cases: Hiding data within photographs or graphics to evade detection.
- Audio Steganography:
- Description: Embedding information within audio files by manipulating the sound frequencies or amplitude.
- Use Cases: Concealing messages or files within music tracks or voice recordings.
- Video Steganography:
- Description: Hiding information within video files by modifying frames or encoding data in the video stream.
- Use Cases: Concealing data within video content to avoid detection.
- Text Steganography:
- Description: Embedding information within text documents by using techniques like modifying font spacing, invisible characters, or subtly altering the text.
- Use Cases: Hiding messages within seemingly innocuous text.
- File Steganography:
- Description: Concealing data within various file formats, such as documents, PDFs, or archives, by manipulating the file structure or incorporating hidden data.
- Use Cases: Hiding information within commonly used file types.
- Network Steganography:
- Description: Concealing data within network protocols or traffic by manipulating packet headers or payload.
- Use Cases: Evading network-based detection systems by hiding malicious activities within legitimate traffic.
- Print Steganography:
- Description: Embedding information within printed documents by imperceptibly altering patterns or colors.
- Use Cases: Concealing data within printed materials to transmit information covertly.
- Email Steganography:
- Description: Hiding information within email communications by manipulating the email headers, formatting, or attachments.
- Use Cases: Concealing malicious payloads or exfiltrating sensitive information via email.
- Social Media Steganography:
- Description: Concealing information within images, videos, or messages shared on social media platforms.
- Use Cases: Hiding messages or data within publicly shared content.
- Binary Steganography:
- Description: Embedding information within binary code by manipulating specific bits.
- Use Cases: Hiding data within executable files or other binary formats.
- Metadata Steganography:
- Description: Concealing information within the metadata of files, such as image EXIF data or document properties.
- Use Cases: Hiding information that may not be immediately visible but is embedded in file metadata.
- Printed Text Steganography:
- Description: Embedding information within printed text by subtly altering the appearance of characters.
- Use Cases: Hiding data within printed materials to transmit information undetected.
These steganography techniques can be employed for both legitimate and malicious purposes. While some applications use steganography for digital watermarking, copyright protection, or data embedding, cyber attackers may use it to hide malware, exfiltrate sensitive information, or conduct covert communication. Detection of steganographic attacks requires advanced analysis tools and techniques to uncover hidden information within seemingly innocuous data.
Steganalysis is the process of detecting the presence of hidden information within digital files, a practice known as steganography.
Steganalysis techniques aim to identify and reveal the covert communication or information concealed in images, audio files, videos, or other data carriers.
Here are some common methods used for detecting steganography:
- Statistical Analysis:
- Description: Analyzing statistical properties of the carrier file, such as image histograms, frequency distributions, or correlation coefficients, to identify deviations from the expected patterns.
- Use Cases: Steganographic content might introduce subtle changes in statistical properties that differ from those of regular files.
- File Size Analysis:
- Description: Comparing the file size of the suspect file with similar non-suspect files of the same type. Steganographic additions often result in an increase in file size.
- Use Cases: Steganographic alterations can cause slight increases in file size that may be detectable through careful analysis.
- Visual Inspection:
- Description: Manually examining carrier files for unusual visual artifacts or irregularities that may indicate the presence of hidden information.
- Use Cases: Visual cues, such as variations in pixel patterns or colors, may be visible in images with steganographic content.
- Frequency Domain Analysis:
- Description: Analyzing the frequency domain of signals, especially for images and audio, to detect anomalies or patterns associated with steganographic techniques.
- Use Cases: Steganography may introduce specific frequency patterns that differ from those found in unaltered files.
- Metadata Analysis:
- Description: Inspecting metadata information embedded in files, such as EXIF data in images or document properties, to identify inconsistencies.
- Use Cases: Steganographic content might alter metadata, and careful examination can reveal discrepancies.
- Machine Learning Techniques:
- Description: Utilizing machine learning algorithms to train models on known steganographic and non-steganographic data, enabling automated detection.
- Use Cases: Machine learning can be effective in identifying subtle patterns that may be challenging for manual analysis.
- Entropy Analysis:
- Description: Calculating entropy values within a file to measure randomness. Steganographic additions may alter the entropy of the carrier file.
- Use Cases: Hidden information may introduce specific patterns that deviate from the expected randomness found in regular files.
- Benford’s Law Analysis:
- Description: Applying Benford’s Law, which describes the expected distribution of leading digits in naturally occurring data, to identify irregularities in steganographic content.
- Use Cases: Steganographic alterations may result in non-compliance with the expected distribution according to Benford’s Law.
- Consistency Checks:
- Description: Conduct consistency checks on various components of the carrier file, such as checksums or hash values, to identify alterations.
- Use Cases: Steganographic additions may disrupt the integrity of the file, leading to inconsistencies in checksums or hashes.
- Error Level Analysis (ELA):
- Description: Comparing error levels introduced during compression to identify areas where steganographic content may have been added.
- Use Cases: Changes in error levels may indicate the presence of hidden information introduced during the steganographic process.
Detection of steganography often involves a combination of these techniques, and the effectiveness may vary based on the complexity of the steganographic method used. Advanced steganalysis tools and methodologies are continually evolving to keep pace with new steganographic techniques and improve detection accuracy.