Malicious PDF — malware analysis report

Static analysis result for SHA-256 309471a1d1bf7688…

MALICIOUS

PDF

73.3 KB Created: 2021-06-20 18:06:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 4117d52bde9c22e72741d66ba8583342 SHA-1: 928efab343d2dc740e008799ed9bec77679f421b SHA-256: 309471a1d1bf76880cc9fd0b2d14204c3d4e2690aa9edb54778fb2ee090d4326
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF file contains a link farm pointing to compromised websites, designed to trick users into downloading a "free VPN". The ML classifier and ClamAV detection strongly indicate malicious intent, likely to deliver a phishing payload or malware. The presence of external URIs and a link farm on disposable hosting further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://coretry.ru/uplcv?utm_term=tom+vpn+free+download+for+windows+10 PDF link annotation
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcffd2eb448---69414044236.pdfIn PDF document text
    • https://mk-promotions.com/ckfinder/userfiles/files/17236495201.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082f8e2604e0---65472537773.pdfIn PDF document text
    • http://mmdplus.com/userfiles/files/20210606_071824.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/16081f57f9e073---piguwifupidapenuridu.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8bd765107e---nevevomavejoxurefisopoz.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/03198accd23ef457fb9a0b0b3b4c52b9/ruber.pdfIn PDF document text
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/etuftlabp2r1kejfb49dqnth1k/xonepiw.pdfIn PDF document text
    • https://weeb.nu/userfiles/file/buduxibomukoduvogubowovub.pdfIn PDF document text
    • http://www.rify.us/cms-uploads/files/jurosoni.pdfIn PDF document text
    • https://ukdirectremovals.com/wp-content/plugins/super-forms/uploads/php/files/4e16129c76d752b1167f17f7b5fbc963/70268377692.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/q66kvhmdvp6lhe3l0nlj8mksq9/daredojufakudapezeb.pdfIn PDF document text
    • https://soba05.org/wp-content/plugins/super-forms/uploads/php/files/3f02b566e9c17caccf84285b925be8ed/bodar.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074506307a49---kaburebubipotilematamana.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160738f5763c4e---rolivelaganateg.pdfIn PDF document text
    • http://innotack.com/userfiles/files/rufilokaj.pdfIn PDF document text
    • http://cnex.cc/images/blog//file/baraf.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e0a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0A5 5484 bytes
SHA-256: 526bfb6f62efd18fac576b16fb6756ce0a824a80fc99d9e1c763916dc297fa81
font_01_sfnt_off0000f350.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF350 10896 bytes
SHA-256: c9e1198678fc1f9e1c9024793451e85478b1edb197e61e314e01646aadb59d45