Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c757631e91ac15b…

MALICIOUS

PDF

69.6 KB Created: 2021-09-11 21:04:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 49c36510a023f44acf3c9b98f9b4a1a3 SHA-1: 5f15551f23ab314ab8c65a216a125071cbe51074 SHA-256: 7c757631e91ac15b578267ac5347fb1b491360a6d51d09e7f9bbc91e5593f4f3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many pointing to domains associated with link farms and SEO manipulation, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing unwanted content. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a malicious document designed to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://daynexweb.com/upload/ckfinder/files/90491918857.pdf In PDF document text
    • https://cezartravel.hu/userfiles/file/13321408531.pdfIn PDF document text
    • http://photou.cc/ckfinder/userfiles/files/31689836052.pdfIn PDF document text
    • https://mgs-on-track.com/uploads/misc/files/nowagexabitoxupa.pdfIn PDF document text
    • http://cuacuonnhaxuongbinhduong.com/upload/files/23578387967.pdfIn PDF document text
    • https://lrdreamteam.com/files/files/file/InfoProduct/file/20016794679.pdfIn PDF document text
    • http://thienlongadv.com/upload/files/45029639918.pdfIn PDF document text
    • https://www.jaegeraviation.com/ckfinder/userfiles/files/46754428819.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16136a64963e1c---nowezagim.pdfIn PDF document text
    • http://wsystem.sk/userfiles/files/21966851047.pdfIn PDF document text
    • http://thegioioto.store/upload/files/98009558889.pdfIn PDF document text
    • http://bbfederico2.net/userfiles/file/57739489959.pdfIn PDF document text
    • http://leebyunghun.kr/new/upload/board/files/wefew.pdfIn PDF document text
    • https://indicaperu.com/userfiles/file/xadebutatifokorisi.pdfIn PDF document text
    • https://atlantidegattico.it/file/samilobukanupuredusir.pdfIn PDF document text
    • http://chiengthai.com/file_media/file_image/file/tumamo.pdfIn PDF document text
    • https://coastalholidayproperty.com/ckfinder/userfiles/files/65313194527.pdfIn PDF document text
    • http://kieryk.pl/img/userfiles/file/mafivaza.pdfIn PDF document text
    • http://gddfboiler.com/uploads/files/91895032390.pdfIn PDF document text
    • http://ideal-site.ru/userfiles/file/pirunukonobobaju.pdfIn PDF document text
    • https://dla-pracownika.pl/pliki_user/File/20193282165.pdfIn PDF document text
    • https://dammesliepas.lv/ckfinder/userfiles/files/sofute.pdfIn PDF document text
    • http://himalayakebab.irafbrothers.com/shipinc/userfiles/files/47041112060.pdfIn PDF document text
    • https://xedulichhaiphong.vn/images/news/files/71651569613.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=clash+of+clans+private+server+iphonePDF link annotation
    • 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_off0000b14c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB14C 15468 bytes
SHA-256: 23bbf29d3264cd1ea2246c55db41ca510ddbf92f8a2165c6f483dd24e98d2112
font_01_sfnt_off0000d860.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD860 10672 bytes
SHA-256: 958397421ce21ec396e5f834581dc6fdd96de16b2f55271182afe15bc8f8f80b
font_02_sfnt_off0000f0d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1