Malicious PDF — malware analysis report

Static analysis result for SHA-256 c28cc320d7803455…

MALICIOUS

PDF

86.2 KB Created: 2021-09-18 10:24:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 74742def77147e0659b3c891d77cea1b SHA-1: f0ed4fa4c0670b999a57d177b2b751c787c50cb2 SHA-256: c28cc320d7803455789f7a353fd21d284d1ab5205621f65853f85383dafcf635
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised CMS uploads or disposable hosting. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure suggests a link farm designed to redirect users to potentially malicious content or for SEO manipulation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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 https://unitytradefze.com/ckfinder/userfiles/files/wifozoruxefuxukenepeto.pdf In PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16142280ff3f38---37440358398.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/18053259179.pdfIn PDF document text
    • http://arc-en-cielproduce.com/ckfinder/userfiles/files/2452364920.pdfIn PDF document text
    • http://kargiskola.ge/myadmin/ckeditor/ckfinder/userfiles/files/kolevamatakopijimij.pdfIn PDF document text
    • https://parc-hotel.info/file/fesekomiledelosavutumobo.pdfIn PDF document text
    • http://nilesk.com/userfiles/file/74298242697.pdfIn PDF document text
    • http://universalgroupautos.com/files/others/vosuwufibunudatijexi.pdfIn PDF document text
    • http://himalayakebab.com/shipinc/userfiles/files/93513296568.pdfIn PDF document text
    • https://dusunceokulu.net/resimler/files/dirisokuxalubi.pdfIn PDF document text
    • http://ebonit.light.bg/includes/libs/ckfinder/userfiles/files/remigusekunexenij.pdfIn PDF document text
    • https://serpavenger.com/ckfinder/userfiles/files/35815394494.pdfIn PDF document text
    • https://knoxvilleremembers.com/media/10646733571.pdfIn PDF document text
    • http://bdsductri.com/upload/files/57771872217.pdfIn PDF document text
    • http://gbfrjournal.org/pds/userfiles/files/5491434699.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/31fe515008432ed73f413b8b00cf05fe/tupigusaloniwunosa.pdfIn PDF document text
    • http://smartpaintingplus.com/userfiles/files/fubonovizoziwev.pdfIn PDF document text
    • https://keluargamimpi.com/contents/files/54158445009.pdfIn PDF document text
    • https://billard-hauri.ch/userfiles/file/79994269777.pdfIn PDF document text
    • http://qiuyutv.com/userfiles/files/20210905022911.pdfIn PDF document text
    • http://otczenacts.com/media/files/71097015650.pdfIn PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/lrq177t281e4hh0lmopouo8ic4/sizuwubip.pdfIn PDF document text
    • https://girisimhaber.com/uploads/file/sejavetesanoroso.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ccb723ed56---60553415762.pdfIn PDF document text
    • http://tdsns.ru/userfiles/file/29625458102.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=pokemon+adventures+romPDF 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_off0000ed48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED48 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001055f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1055F 10528 bytes
SHA-256: e07a02d8ab9c7b044e9bcf7d49e3915844e5dcada80e1469d59170222f7dde11
font_02_sfnt_off00011d66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D66 17500 bytes
SHA-256: 66c0c9cbf0eefdb69aa2b4b1311a0071d98792831b44a2cc02d8d0dd2b2b715b