Malicious PDF — malware analysis report

Static analysis result for SHA-256 65f8cd89d3507ce5…

MALICIOUS

PDF

73.5 KB Created: 2021-09-06 18:55:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 51f28f4f4f813cea07cd39e52d91cfdd SHA-1: 8d2ad255ae9c01a706964c4821764a77e2c8a7ca SHA-256: 65f8cd89d3507ce5484ec94c5aa4d811b2925fc079ed9ef0f29f963f9ec01c03
156 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating it's part of a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were extracted, the presence of numerous external links, including one to a compromised WordPress upload, indicates the PDF is likely used to redirect users to malicious sites for phishing or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://masan315.net/board/imagefile/file/ganagulosegulevilowawan.pdf In PDF document text
    • http://tks-forever.com/upload/2021/07/29/file/13785808288.pdfIn PDF document text
    • http://studiorestagno.eu/userfiles/files/40545420004.pdfIn PDF document text
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/e2k3bsf7t5ic4k8o02got526p4/1524606333.pdfIn PDF document text
    • http://contextuae.com/resimler/files/vitatijatilo.pdfIn PDF document text
    • https://walnutcreekguide.com/wysiwygfiles/file/sarerexakamakabipobedi.pdfIn PDF document text
    • http://robertsrucker.com/clients/7/7f/7f5ecd1287ec2152c36a7dc1808edcbf/File/jolejenatixi.pdfIn PDF document text
    • https://sonerofset.com/userfiles/file/175717245.pdfIn PDF document text
    • https://reitinguok.lt/userfiles/file/33248923898.pdfIn PDF document text
    • http://mclarenquartz.in/ci/userfiles/files/60992239489.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/vtl3r97gd7v81199a9l79h5345/jurafexedivimotarej.pdfIn PDF document text
    • http://grupophi.es/uploads/files/jenojolaxovelexivemu.pdfIn PDF document text
    • http://happyhanool.com/ckupload/files/xigorufovesuxiduje.pdfIn PDF document text
    • https://dolnoslaskialarmsmogowy.pl/imgturysta/files/50002726558.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607edf8300044---79318315599.pdfIn PDF document text
    • http://enjoy.sk/editor_uploads/system/files/jujuvowiritus.pdfIn PDF document text
    • http://techscreening.com/userfiles/files/16555225572.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/huaqfdq0ide9ntavqjnt57vh8f/likerebemegifozuledo.pdfIn PDF document text
    • http://vhz.cz/user-files/5247207175.pdfIn PDF document text
    • http://www.anjhimayath.com/upload/file/78037300726.pdfIn PDF document text
    • http://profil-metall.de/content/uploads/file/pofelobazi.pdfIn PDF document text
    • https://vaytieudungtragop.com.vn/wp-content/plugins/super-forms/uploads/php/files/jk5g86ikglict8c67djt52bc89/folekafavededinagar.pdfIn PDF document text
    • http://pkynfe.net/userfiles/file/welamukuxavavonojukuped.pdfIn PDF document text
    • https://t2sc.me/userfiles/vazarekamutovosowop.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=langmuir+and+freundlich+isotherm+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_off0000bb82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB82 16788 bytes
SHA-256: 435f4945a6c4c30462e5052b9073822fbd043371113dc7670366463708b8d06a
font_01_sfnt_off0000e708.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE708 11124 bytes
SHA-256: 87b87f796d4438f37871f1d13805b777fd9eeaf3f51bf7e0ec60b84cfe96877c
font_02_sfnt_off00010092.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10092 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1