Malicious PDF — malware analysis report

Static analysis result for SHA-256 b95173586b7ba7c8…

MALICIOUS

PDF

69.9 KB Created: 2021-09-30 16:21:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 40987289781baabcbacd71b818b4b0b8 SHA-1: 269d84a69f44921b072b1ff9754983ec83f2693b SHA-256: b95173586b7ba7c86af283603289bc27a920d54298934475bf58e6b6b3ed4db6
196 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://35ju.21tg.cn/uploadfile/ckeditor/files/jegipidipekopadonefuxoz.pdf
    • https://cambodiadriverservice.com/userfiles/file/77733078720.pdf
    • http://sculecuacumulator.ro/app/webroot/files/userfiles/files/82030503510.pdf
    • http://germainelecocq.it/userfiles/files/35993733492.pdf
    • https://www.techsrollout.com/wp-content/plugins/formcraft/file-upload/server/content/files/161467a8a34731---80298552845.pdf
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/1qt892h6iitj8phevp2lkbda0i/wadokovajulalirizosiloge.pdf
    • http://kimsanghun.com/upload/userfiles/file/20219222316484613.pdf
    • http://ankurgroups.com/userfiles/file/pezonebid.pdf
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613606dd25e04---genikajenudi.pdf
    • http://raylutickenterprises.com/userfiles/files/73909869705.pdf
    • http://plenerowe.kbo.pl/ckfinder/userfiles/files/piluwam.pdf
    • http://oldadmin.k12cart.com/media/files/lebemilo.pdf
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/1614c195302924---nofivoleguwepabawirup.pdf
    • https://xuantruongtech.com/images/ckeditor/files/70548178884.pdf
    • https://actaviaserica.org/board/file/files/woxunutigizagivetifi.pdf
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/fe4e49e87f4bc4d1792297d5f5185f0e/39098182390.pdf
    • http://xingyeknitting.com/userfiles/files/xomajesep.pdf
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/c2a2bd5c7a58d8a3e447c66745f47594/jefelisunagezo.pdf
    • http://crmrealty360degree.in/ci/userfiles/files/95486334024.pdf
    • http://studiomuraca.eu/userfiles/files/kixomogibafele.pdf
    • https://trimix.bg/UserFiles/File/7855521293.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/0fsuh37a12nncjvdcfd27bfer7/74630582167.pdf
    • https://krzczonowice.pl/gfx/file/sevuneru.pdf
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613c75718087b---96069287173.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=why+does+my+android+phone+keep+freezing+up
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b3e2.bin
e29cc60a2e7c4ab3f77915d1d365e5ca17193404a83ee04accd7b851e7725f4d
pdf-font-stream PDF embedded font (sfnt) at offset 0xB3E2 11160 bytes
font_01_sfnt_off0000cda1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCDA1 16792 bytes
font_02_sfnt_off0000e5b3.bin
9008e4887b577cce0196e00f6e6762ce866ab568522d16a5cfc706b4b0986465
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5B3 14332 bytes