Malicious PDF — malware analysis report

Static analysis result for SHA-256 17dfb757a5667e77…

MALICIOUS

PDF

74.2 KB Created: 2021-10-03 01:26:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 8877631f1c9b190fd4979056e16a7fc5 SHA-1: 8db1d4175102ed1e91074c60d22dda52152314cb SHA-256: 17dfb757a5667e775ea11041664926e168bbd3c8b7279984a5096f74bac427c3
164 Risk Score

Malware Insights

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

The sample is a PDF document containing embedded JavaScript, which is a common vector for exploiting vulnerabilities. Heuristics indicate it's a link farm pointing to compromised upload storage, suggesting it's designed to host and distribute malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to download and execute a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9907

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://szamitogep-szerviz-javitas.hu/ckfinder/userfiles/files/7540541793.pdf In PDF document text
    • http://gibisch.biz/files/files/vegifinekifuboxoxobuju.pdfIn PDF document text
    • https://stotex.rs/files/15753734066.pdfIn PDF document text
    • https://centaur.vri.cz/docs/files/73444033399.pdfIn PDF document text
    • https://marathonblainville.com/userfiles/files/lejafovizufomuzatav.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139472947fb7---fufofuzemukufatufo.pdfIn PDF document text
    • https://simplehome.ro/ckfinder/userfiles/files/70895469486.pdfIn PDF document text
    • https://trexanh.net/upload/files/73943368369.pdfIn PDF document text
    • http://www.trisad.kz/ckfinder/userfiles/files/jigalu.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f0f54874dc---tadiboxek.pdfIn PDF document text
    • http://wonderpanel.com/app/webroot/img/file/logupewefatoxiz.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/5d2jdqeig677i72ohmraa7os44/84716447295.pdfIn PDF document text
    • https://bharatceramics.in/ckfinder/userfiles/files/59455995491.pdfIn PDF document text
    • http://smartpaintingplus.com/userfiles/files/zemodevupenofasa.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614eaaa731c6d---6203353474.pdfIn PDF document text
    • http://allmedicus.com/userfiles/file/morukawotejowoxavolanosi.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/0jg5r8inf7eolgh0qv4ngdn5p2/86297644887.pdfIn PDF document text
    • http://xn--80aafbladvtgxneccoge3bt.xn--p1ai/pict/file/tepibufiz.pdfIn PDF document text
    • https://www.channeloflove.com/ckfinder/userfiles/files/mudapaki.pdfIn PDF document text
    • https://bankkartya.hu/js/ckfinder/userfiles/files/depofituzowibuloxo.pdfIn PDF document text
    • http://chonburi33.com/userfiles/file/3503120376.pdfIn PDF document text
    • http://miet-boot.ch/images/uploadedimages/file/xirebipuwininan.pdfIn PDF document text
    • http://xn--h1aaebajlcgx.xn--p1ai/sadm_files/52188091053.pdfIn PDF document text
    • https://plasy.com/uploads/file/watetuw.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/sebabixo.pdfIn PDF document text
    • https://marblobaths.com/app/webroot/img/files/71417860597.pdfIn PDF document text
    • http://myoffice2561.sesao33.net/UserFiles/File/fetoporinefaza.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=seed+ocean+monument+minecraftPDF 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_off0000bb9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB9B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d3b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3B2 10596 bytes
SHA-256: 5f50cb7e2df27d5f5b9c67802d67f20dddac7982b32d1c6e0d8d99d672489e22
font_02_sfnt_off0000ebe2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBE2 18384 bytes
SHA-256: 8915059178ea7e24a71703edb6d1fc841e437beb275d06274cb7d4c2581a142d