Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3fbbb82591d2847…

MALICIOUS

PDF

110.2 KB Created: 2021-07-26 11:16:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: a29ec1a6c47820531203b945ee375a5e SHA-1: 404b902a601b50aeec771f47ac6d3f27411bc556 SHA-256: b3fbbb82591d28472951ccd3d5dd3f257bf7dc69f23a4c8b38a4d7f490337580
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or are hosted on disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware delivery. The presence of multiple external URIs and link farm heuristics supports the classification as a malicious link distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://finatwork.com/userfiles/file/lagot.pdf In PDF document text
    • http://cafehinglung.com/uploads/files/bunanofupewememuzotoze.pdfIn PDF document text
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/21c1631ff5edb08361c08ad5577d5f03/firunofamiva.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1a2d74f49a---99866460915.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/54008173914.pdfIn PDF document text
    • http://www.misshandicap.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16076a46e284ff---suraxumikuvelozowati.pdfIn PDF document text
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/cb4370ebac60e225db85922b097c937b/28001867884.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/eogqvplrukmnr5qnc6cj5q1867/vijarexawubutufigejigorum.pdfIn PDF document text
    • http://iltorg.ru/upload/file/lupirarutewixijipudifet.pdfIn PDF document text
    • https://lightingsystemscol.com/wp-content/plugins/super-forms/uploads/php/files/8423d6a2ec87133f61c3a811f063d645/sajapere.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/16072bdb71abf2---37147435540.pdfIn PDF document text
    • https://legacyltg.com/wp-content/plugins/super-forms/uploads/php/files/ac93a6cd95c83f9124ccab99d04e3135/bewilizopebodufubuj.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/a29d912fdf27854101745c1f6c397c81/67203977248.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/658aaf357659e0600fe13e97b65f0e6b/gipuvan.pdfIn PDF document text
    • https://stegopackaging.com/wp-content/plugins/super-forms/uploads/php/files/1fjf2dbnjtkssva6of4unkqkrr/nivolojolenik.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/68616528386.pdfIn PDF document text
    • http://neonyazilim.com/images/Media/files/40857223497.pdfIn PDF document text
    • https://miaousland.fr/ckfinder/userfiles/files/4464933018.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160941fdcb276b---renofinodudigeluradubob.pdfIn PDF document text
    • http://flemingdecal.com/uploads/assets/file/6236930340.pdfIn PDF document text
    • http://litho-and-co.fr/ckeditor/upload/files/80961630976.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16079f2dc43419---2603954430.pdfIn PDF document text
    • https://nattasampun.com/upload/files/44243246261.pdfIn PDF document text
    • https://majorsagilekvaros.hu/uploads/file/segilobedurazulobegu.pdfIn PDF document text
    • http://ligneus.hu/upload/file/41907573036.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=nfl+rush+scrambled+legsPDF 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_off00014b6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14B6F 10728 bytes
SHA-256: a317304cc601981bed0d9ec9a531b3b3f30c539ec07770bf553880e5f3160551
font_01_sfnt_off000163df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x163DF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00017bf1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17BF1 17920 bytes
SHA-256: 360b6f3b9ef5e99b87dd58ddc1c6432490c08d20fda69a818f48352ac89c4bdc