Malicious PDF — malware analysis report

Static analysis result for SHA-256 12c35ba45026256d…

MALICIOUS

PDF

80.7 KB Created: 2021-09-09 03:35:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 76c83290183f458e576b35a8d16a2981 SHA-1: 378cf71960f39133996683b227b1def3efd2e80b SHA-256: 12c35ba45026256dc5308c8695f7cf047666fa7d2e44e7597e060ef60bc16b7e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to potentially disposable domains, suggesting a link farm or phishing lure. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the PDF is designed to host many links on various domains. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://k-newsletter.com/ckupload/files/54822198511.pdf In PDF document text
    • https://nibrasimansch.com/userfiles/files/71206521954.pdfIn PDF document text
    • http://toitureetfacade.fr/data/Files/manapirikeno.pdfIn PDF document text
    • http://interface-referencement.com/userfiles/file/naradipanonileniwiwigipuv.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/d59bb5126918959e548b3e4b9487bbde/59228382209.pdfIn PDF document text
    • http://sport-zavora.cz/data/file/lilonupop.pdfIn PDF document text
    • http://animationcoach.com/userfiles/file/jatate.pdfIn PDF document text
    • http://3e-recycling.ru/app/webroot/filesfiles/fogujisupapajaxepudonuv.pdfIn PDF document text
    • https://tidurmalam.com/contents/files/20538536648.pdfIn PDF document text
    • https://suthuytinh.com/app/webroot/uploads/files/tulotawuwe.pdfIn PDF document text
    • http://pieseclimaauto.com/files/file/20460869734.pdfIn PDF document text
    • http://stitesattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/82373055374.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/botopomininobirix.pdfIn PDF document text
    • https://maxlinder.com/admin/assets/ckfinder/userfiles/files/musikoxobenetoxed.pdfIn PDF document text
    • https://villadelauca.com/userfiles/file/90785296595.pdfIn PDF document text
    • http://4reality.cz/userfiles/files/xedegoma.pdfIn PDF document text
    • http://dienmaythanglong.org/uploads/files/vofunumadob.pdfIn PDF document text
    • http://szyuangang.com/UserFiles/file///fakapo.pdfIn PDF document text
    • https://alariel.be/userfiles/file/wewisuvomuf.pdfIn PDF document text
    • http://www.phuongdonggolf.vn/app/webroot/uploads/files/betosapulobok.pdfIn PDF document text
    • http://hpworld.hu/data/pic/Image/file/59390319912.pdfIn PDF document text
    • http://finproekt-msk.ru/userfiles/file/vivomuwudabadasitazanoj.pdfIn PDF document text
    • https://ewt.cz/res/file/dokowidujom.pdfIn PDF document text
    • https://annekienlen.fr/imagesfile/mafupenilubu.pdfIn PDF document text
    • http://globalcenterhotels.com/bot/ckfinder/uf/files/83064946190.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=watch+house+of+wax+1953+online+freePDF 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_off0000d48e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD48E 11240 bytes
SHA-256: 6400acd12f8155e7c7b75a4472bad32f596b74ec191ee6d8fd2a1003f316a806
font_01_sfnt_off0000ef0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF0A 17900 bytes
SHA-256: 14ef41d60571bb531631afd76fa3258c0ad807c5a36434f3e2d4b8b3cf2fae76
font_02_sfnt_off00011db8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DB8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1