Malicious PDF — malware analysis report

Static analysis result for SHA-256 848b5f25f0d59581…

MALICIOUS

PDF

74.8 KB Created: 2021-05-14 13:43:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 2b17f80954c41ee0a25c0e4513325777 SHA-1: 7483bc0aa1fd424b757a50bf000abff449d52af4 SHA-256: 848b5f25f0d59581ab9de1f5ca16cfaac87841543fa373147e64c1e46040e5f1
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of embedded links, many pointing to disposable hosting services, indicating a link farm designed to distribute traffic to malicious sites. One critical heuristic identified links to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the presence of numerous links suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://crophysi.ru/strik?utm_term=epson+gt-s50+repair+manual In PDF document text
    • https://cdn.sqhk.co/getabemuto/WIXidhh/piano_keyboard_chart_with_notes.pdfIn PDF document text
    • https://cdn.sqhk.co/kizofapekeku/Bgjijzu/notegesero.pdfIn PDF document text
    • https://cdn.sqhk.co/giripiponi/ciiyJjd/red_vs_blue_character_quiz_playbuzz.pdfIn PDF document text
    • https://cdn.sqhk.co/minamojazi/hegjhiV/74598707606.pdfIn PDF document text
    • https://kekorozonositen.weebly.com/uploads/1/3/2/7/132710750/6848be51e33.pdfIn PDF document text
    • https://rixagaxovexi.weebly.com/uploads/1/3/4/0/134000332/18f28b7682107.pdfIn PDF document text
    • https://cdn.sqhk.co/famuxina/akw0Wid/vosotizonepu.pdfIn PDF document text
    • https://cdn.sqhk.co/gebunemif/9hfhc44/best_of_2020_songs_english.pdfIn PDF document text
    • http://abreudesigns.com/98503820093razul.pdfIn PDF document text
    • http://giftcard-sale.store/lack_of_a_quorum_meeting8viyr.pdfIn PDF document text
    • https://cdn.sqhk.co/nisugavu/mjahjws/lafokurej.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://4a1cfc67-5981-466d-a13b-75576fe7431f.filesusr.com/ugd/64e449_c4478e432d8b4a6dacf44ff3226331ac.pdf?index=trueIn PDF document text
    • https://2d66045e-c276-4037-81df-184b25840e97.filesusr.com/ugd/cdf3e3_33a9847ca1604c18831826de046e3ca5.pdf?index=trueIn PDF document text
    • https://63b1f34b-4847-450f-8d9a-4788d10e1cf5.filesusr.com/ugd/451a43_79d4690f4a1641389dd3e9d7613b8bda.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7b981cfa-73c5-4a18-a802-b7eed8c37eee/biomedical_engineering_unsw_handbook.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/70044820-6111-44c4-9872-cf1b10a89f52/best_crossfit_workouts_at_home.pdfIn PDF document text
    • https://933527c5-e005-4225-a3aa-05fee46c7696.filesusr.com/ugd/b51dd5_773f0d40b5d04f3591baeb5cb6bb3c03.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7c51b1f1-43b7-42be-9232-98000f83b503/casio_illuminator_watch_sunrise_sunset_world_time.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/64fcd87e-5789-4659-93b6-5fd58f6e2896/pewusudikezunelowiwo.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e897.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE897 5396 bytes
SHA-256: 1310f36f64262ad8aec802aab4917413e59b85a01c30fd96de277138fa863179
font_01_sfnt_off0000faeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAEB 10380 bytes
SHA-256: f56df3e5117d2b8e7f495914ec1a3afd1788d33c7cba0a43ac9a091904ff6c21