Malicious PDF — malware analysis report

Static analysis result for SHA-256 42d31a8bea3f1ffb…

MALICIOUS

PDF

73.5 KB Created: 2021-07-12 22:17:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 7b13cc569e5b4fd33c4626bbb0ba9457 SHA-1: a9289c1d11b71b56325b6293c275f3aae4f6f87a SHA-256: 42d31a8bea3f1ffbf000b2f0fce9c42f7e71758c71d9e86a0da50b5ed49d243e
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated maliciousness. A high-severity heuristic identified an image lure linking to an SEO redirector, specifically the URL https://huntic.ru/square?utm_term=young%27s+chinese+food+carryout, which is likely a phishing lure. No scripts were extracted, but the PDF structure and heuristics strongly suggest a phishing attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7882

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://huntic.ru/square?utm_term=young%27s+chinese+food+carryout PDF link annotation
    • https://static1.squarespace.com/static/60bf6bff0d8d387fecc8b153/t/60e8230a6d117d6eeca70cb4/1625826058601/zatevijatenuxujojowujew.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60ec8af631b0b43e07e78c97/1626114806700/computer_network_operating_system.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac5994c6b1805bc4acbdb/t/60e781661d9e4b182617a42a/1625784678648/i_too_had_a_love_story_free_download.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60e7d892ce8457037ee2828a/1625806994921/96873130645.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c234.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC234 15228 bytes
SHA-256: ce167b1b1957ee5c76b68599812182a80d024cd68b8b3b1c3b13a0011ef6daf3
font_01_sfnt_off0000e8e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8E2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000100f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100F9 10940 bytes
SHA-256: 065ec4e51bc678a8ce009c3137bf3c299243ff8bca8f71ef87f23b4962538ef0