Malicious PDF — malware analysis report

Static analysis result for SHA-256 acd243456ee0313f…

MALICIOUS

PDF

85.2 KB Created: 2021-06-28 20:28:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: dbd1b627a09b2a10d3574717e3703b37 SHA-1: 81fa9d1827e11e58d623665ee3919791848206ab SHA-256: acd243456ee0313fcd2ff5004d9e341fc2783ec2372cd73fd0739712780c9f7a
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to compromised WordPress sites, indicating a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly suggest malicious intent. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the heuristics confirm the presence of external links designed to lead users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b5cc5cd9544---65888602357.pdf In PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606fe5ebd9eef---10170788369.pdfIn PDF document text
    • http://kolkandkolkdesign.com/site/data/ws/files/furevibuf.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/9a7070bf4641750d9ea4ce20e5380c7c/limusegebune.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/10b8a9b82bc2a18ae29949739d2d9680/galakamidutaru.pdfIn PDF document text
    • https://balajitutorial.com/admin/userfiles/file/60902209224.pdfIn PDF document text
    • http://tahi.hu/ckfinder/userfiles/files/xesal.pdfIn PDF document text
    • http://anhuizpyy.com/upload_fck/file/2021-4-28/20210428205821327019.pdfIn PDF document text
    • https://mszukam.pl/dat//file/negilapibotegovupodaru.pdfIn PDF document text
    • https://thietbivesinhanhhuy.com/asset/files/51640327241.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bfa24d1c5e4---85308451520.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/160831b8a6189d---rezafikusejoporusu.pdfIn PDF document text
    • http://lamachine.nl/userfiles/file/52242181192.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/b10070bd593ba25127af4e30841804ad/75878585097.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/178b2e12fe45972c116f8938b575ad8d/5552549884.pdfIn PDF document text
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/f44b9fd54b0bc2e0c974b3201aba5e3a/3108407398.pdfIn PDF document text
    • http://stlnsk.ru/uploads/file/87282497931.pdfIn PDF document text
    • http://portalcom-b2b.es/img/user///file/_0818615001619809046.pdfIn PDF document text
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/0b939392128b1c393d8d631a4db8261f/2856417297.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/1607f5cd18a66b---zavagarerelaragojabim.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/9720e1965b8f0cf78cb991f5073da5b5/85891255415.pdfIn PDF document text
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/95t7ij2289s2s4uoqqejl4u435/vegokapojo.pdfIn PDF document text
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/bvpdqubbkcs9c4cgvlkm38vri2/veresoziwojulizorunetozi.pdfIn PDF document text
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/ubsrn11p4klrtvjkaen3qui713/15404311620.pdfIn PDF document text
    • http://hi-reid-solutions.com/wp-content/plugins/super-forms/uploads/php/files/e2391cd0b2e3896292220d3489a09a5a/48092824979.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=sociology+and+philosophyPDF 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_off0000ea82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA82 17324 bytes
SHA-256: 43daa42ee02364b9aea5be6e509a2e9331079b902032f95985f1c822c14d839e
font_01_sfnt_off0001171c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1171C 10652 bytes
SHA-256: 08672c62a13d6834ab27aa0e9af2a0a175b93345dac936432737fa81eb0c4a62
font_02_sfnt_off00012f22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F22 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1