Malicious PDF — malware analysis report

Static analysis result for SHA-256 cdf39239336e4f11…

MALICIOUS

PDF

83.0 KB Created: 2021-09-04 15:10:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 7207232d9241651ad73d045fb612acdd SHA-1: b7935653d4042e106bb793bf62034eab1534bd61 SHA-256: cdf39239336e4f11ccfab636f171504e328c51d1aafdda73e817f62333b13cfb
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and link farms, with several pointing to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristics and URLs suggest a malicious link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/f7e8153c0ba24d5216d3e4e6dbee0b2f/27684960587.pdf In PDF document text
    • http://astorandblack.net/emailer/userfiles/file/nimolojukupaputudepotas.pdfIn PDF document text
    • http://montpellier-businessplan.fr/mbp/upload/images/images/upload/ckfinder/fubujatikimitefakin.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/0e578fd6443c9408a012a63ecd5a7afd/zevupatumobirebuweso.pdfIn PDF document text
    • http://nowyhotelik.pl/userfiles/file/kovuxafevarareravax.pdfIn PDF document text
    • http://lafenicealcamo.it/userfiles/files/walanesobuvonufifaxis.pdfIn PDF document text
    • http://3qlohas.com/CKEdit/upload/files/teredoxaxuvoxolalo.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d5dc596c21---nunomononikisu.pdfIn PDF document text
    • http://nordicaluminium.ru/userfiles/file/getarenufakopebujiw.pdfIn PDF document text
    • https://neksav.com/upload/ckfinder/files/61863620399.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f8e891d27c---ragewamupipeke.pdfIn PDF document text
    • http://cravaluos.com/ckfinder/userfiles/files/lukosuwefusinenigaze.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b08c50c380f---74134750848.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b303b5976b3---vigewuduverudoju.pdfIn PDF document text
    • http://arkystudio.eu/userfiles/files/milipuwadev.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160762fd3c0359---2763214091.pdfIn PDF document text
    • http://drstevealbrecht.com/wp-content/plugins/super-forms/uploads/php/files/4b02828c53309ec8d15f3e1e70519b05/marori.pdfIn PDF document text
    • http://washchienluoc.com/upload/file/fuwofuzozixi.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/hd324iahitr3fkqf210vmu6hre/26585974336.pdfIn PDF document text
    • http://karinameal.ru/imgdish/files/jubikalakigepidimux.pdfIn PDF document text
    • https://alternatifhirdavat.com/upload/ckfinder/files/25685886111.pdfIn PDF document text
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/468a3282b18885353fc28b22a4c7bf33/jisilusore.pdfIn PDF document text
    • https://groupburuemas1.com/contents//files/solinanixurifanedosi.pdfIn PDF document text
    • http://www.southforconstruction.com/frontend/web/ckfinder/userfiles/files/86226690597.pdfIn PDF document text
    • https://alternatifhirdavat.com/upload/ckfinder/files/letilexoburixorubada.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161294b69e714b---zalij.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=pcie+pinout+pdfPDF 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_off0000e011.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE011 10236 bytes
SHA-256: c5e821f984c86fbbae8b3fc6a5615dc9b5b13bd0d56f53800a6c285d8a7964f3
font_01_sfnt_off0000f727.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF727 18528 bytes
SHA-256: 816f588556c1ee0fe62b26eeebd6c6c0db9abbeb27475fcb62f01d8dc592520d
font_02_sfnt_off0001265b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1265B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1