Malicious PDF — malware analysis report

Static analysis result for SHA-256 a656bd237f02e619…

MALICIOUS

PDF

72.7 KB Created: 2021-09-26 01:28:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 6bb8541bdefdd6478fb10cb6e9a8f954 SHA-1: 84554a53fb941df2105f30e91514e0e88b817508 SHA-256: a656bd237f02e619a9746435617768b5c4306424e819889396aa4d378e02ecd7
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 directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The presence of multiple external URIs and link farm characteristics points to a tactic of luring users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://hkpefa.org/editor_upload/file/vekale.pdf In PDF document text
    • http://micruts.org/userfiles/file/28301240838.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613499a52f90a---zixemuxogo.pdfIn PDF document text
    • http://sistersaviopublicschool.com/userfiles/file/fuletexevaxevulixumuzis.pdfIn PDF document text
    • https://kuwaitpolyurethane.com/ckfinder/userfiles/files/javidafafuwa.pdfIn PDF document text
    • https://energiadirect.pl/application/resources/ckfinder/userfiles/files/lilikigutajuwutifupinajez.pdfIn PDF document text
    • http://zentrumok.com/userfile/files/46801442900.pdfIn PDF document text
    • https://maritime-models.com/userfiles/file/24835673347.pdfIn PDF document text
    • https://yuvasarkar.org/userfiles/file/85632471090.pdfIn PDF document text
    • https://crcnueva.naturasoftware.com/uploads/images/files/nidekinalupikaben.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613ca33fdbf2d---butokukirixovibimujiba.pdfIn PDF document text
    • https://europawindow.com/app/webroot/img/main_content/files/55033252988.pdfIn PDF document text
    • http://kolesa.sk/files/48174939207.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/161385f0a2ad54---zesopedemufexuderoxujerox.pdfIn PDF document text
    • http://style4.allwebeasy.com/userfiles/files/xugobibomop.pdfIn PDF document text
    • http://fairfresh.net/assets/admin/ckeditorimage/files/neselaxujunimudip.pdfIn PDF document text
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/n9gudbbch0vqbeip4hlv088jbt/75523580399.pdfIn PDF document text
    • https://agencement-menuiserie-var.fr/stockages/files/xodivekazorekiwilovijis.pdfIn PDF document text
    • http://tce.vn/imagesflashupload/file/jikexas.pdfIn PDF document text
    • http://cuacuonnhaxuongbinhduong.com/upload/files/naninagoxamizedijatezati.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613d2818d6c9a---tofenorita.pdfIn PDF document text
    • https://flims.atelierleuthold.ch/userfiles/files/masudiwumilaxoseruxaruke.pdfIn PDF document text
    • http://kagoshimakojintaxi.com/userfiles/file/2653471170.pdfIn PDF document text
    • http://www.louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/2341756720.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/114a755f0dbec19e001359371fc5cb75/60414200546.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=need+for+speed+most+wanted+download+for+pc+windows+7+32+bitPDF 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_off0000b5db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5DB 11328 bytes
SHA-256: ee991f498772351090c511d4b2530391d054bd0643103b3fa045f39ca22eccb7
font_01_sfnt_off0000d07d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD07D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e88f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE88F 16388 bytes
SHA-256: 179916c1d75cb6b8f2766321e4014b850c1def88f39642ec104c95367471fb79