Malicious PDF — malware analysis report

Static analysis result for SHA-256 c41f39ada5e4d528…

MALICIOUS

PDF

82.2 KB Created: 2021-09-02 11:50:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: a309678aacacc51e73fa031eff19641c SHA-1: d08e5054a7c1ebf163624de51231d5c981f90805 SHA-256: c41f39ada5e4d528e56744ca350520a7faf753f9a7d54110e4e3f00ebea0dffa
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the PDF contains a link farm pointing to compromised CMS uploads and disposable hosting, suggesting it's used to redirect users to malicious sites. The presence of numerous unknown URLs further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://driver-jazda.pl/upload/file/kimomorivegivaluzuwepa.pdf In PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/a1e6fe19412706dba8f07e00b8616af8/nozulakimaxenuxuwurekiwit.pdfIn PDF document text
    • http://101-games.ru/images/uploads/files/vazukidomobubetanomo.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/efc200tc8grmb7qb9ejmrucub3/62399188126.pdfIn PDF document text
    • http://truthtube.com/UserFiles/file/xuzusi.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/qof40pnbjm5n2v0jsd1tq5gc98/movazepugisawutadal.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608fe5473869e---junopixuvivoku.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608409318b38f---6807804639.pdfIn PDF document text
    • https://istanajp2.com/contents//files/wupalenatironibenapeb.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/ce81d46331b8c1861e7fe4aaef3e704c/xedikufobutuvajudumaf.pdfIn PDF document text
    • http://zimmerei-possert.at/70011924233.pdfIn PDF document text
    • https://emauto.lv/index/images/up/file/68823949151.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/0677633e1add39ab31c5df0901a43bdd/zelofesofu.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/acc5bee06105d5b48229e90acbfbc300/64585105015.pdfIn PDF document text
    • http://trevelci.ru/ckfinder/userfiles/files/21213330150.pdfIn PDF document text
    • http://msinziniering.com/userfiles/file/nutuvuxofefam.pdfIn PDF document text
    • https://mepho.hu/ckfinder/userfiles/files/26108802808.pdfIn PDF document text
    • http://luckdidea.com/ckfinder/images_store/files/bapikuxubenekujaxutinuta.pdfIn PDF document text
    • http://maskaevlawyer.ru/userfiles/file/80766605181.pdfIn PDF document text
    • https://linhngapt.vn/upload/files/11683255616.pdfIn PDF document text
    • http://humanlitech.com/files/files/basonosamuvo.pdfIn PDF document text
    • http://kochamsushi.pl/UserFiles/file/todubewifobukapu.pdfIn PDF document text
    • https://ensasoft.com.tr/wp-content/plugins/super-forms/uploads/php/files/ae9mmb24jnulatusc2tqlccs4v/retalinu.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160c25095778df---18126721583.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=nuevo+curriculo+nacional+2019+pdf+descargarPDF 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_off0000dba8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBA8 17564 bytes
SHA-256: ab3cff7660f4f00514748091bcaf6419a37298c946093096cbb23f80535f8a18
font_01_sfnt_off0001083d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1083D 11304 bytes
SHA-256: 39af03e8c27d2231ee668299d5abe9c6ec58f77d2e1026e22be4539df957e2f8
font_02_sfnt_off000122cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1