Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bdb227e04135cc1…

MALICIOUS

PDF

81.8 KB Created: 2021-09-19 20:06:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ab05a5275efad6b885e29f52ffaf0122 SHA-1: 41b9ecf11705103693aa2177923642af528fad45 SHA-256: 4bdb227e04135cc17e6e262f4b516e6e65f177fe9d1fdbda83b9ae95875d3934
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The primary attack pattern involves luring users through these links, likely for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://queure.ru/uplcv?utm_term=how+to+take+screenshot+of+this+mobile PDF link annotation
    • http://yossy.biz/userfiles/file/gazalonezarabuxawopuge.pdfIn PDF document text
    • http://www.darvidproperty.com/news/file/76137042387.pdfIn PDF document text
    • http://perles-del-beya.com/userfiles/file/sunivafuzimesezi.pdfIn PDF document text
    • http://studio-rivetti.it/userfiles/files/8475659565.pdfIn PDF document text
    • http://knx-shop.ru/admin/ckfinder/userfiles/files/fufigufoxajavagawo.pdfIn PDF document text
    • http://artepcb.com/upload/files/31786407644.pdfIn PDF document text
    • https://pastelbuilders.com/userfiles/file/91843082533.pdfIn PDF document text
    • http://eaas-journal.org/survey/userfiles/files/50356660250.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/384469febab28e44e7ed7da64ef7894e/kufule.pdfIn PDF document text
    • http://neoneophytou.com/ckfinder/userfiles/files/20140808045.pdfIn PDF document text
    • https://bodykneadstherapy.com.au/ckfinder/userfiles/files/padaxezivowiw.pdfIn PDF document text
    • https://audit-advisers.com/userfiles/file/jawulurojoneses.pdfIn PDF document text
    • https://motoralbini.it/files/file/1409315957.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16137771e900f9---8188271236.pdfIn PDF document text
    • https://lescourailleurs.com/upload/editor/file/panub.pdfIn PDF document text
    • https://trsoftyazilim.com/genelresimler/file/gikovog.pdfIn PDF document text
    • https://parfumzone.ro/files/file/mixatebara.pdfIn PDF document text
    • https://alsharqcc.com/userfiles/files/mejosazafuzonamezevez.pdfIn PDF document text
    • http://tykhchem.com/upload/files/vezarazamuguposewozavim.pdfIn PDF document text
    • http://alnoorcity.com/userfiles/file/kemimokasa.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/cd1358a7c2e451f55fdedb5e23546657/39369488649.pdfIn PDF document text
    • http://jnnycc.org/userfiles/file/43671830113.pdfIn PDF document text
    • http://vasekurzy.cz/userfiles/file/dezusevamuraduzageseb.pdfIn PDF document text
    • http://dailyliving.nl/ckfinder/userfiles/files/1936941297.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_off0000d906.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD906 10908 bytes
SHA-256: 173eea2498f19c7900c9af5ceb1986b00dc91389e1d4972bd3bd35879ffb4263
font_01_sfnt_off0000f213.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF213 18108 bytes
SHA-256: 72fe832b0324395749fda13e233d0308835c094be8bf2835727021b6f7348543
font_02_sfnt_off0001215b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1215B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1