Malicious PDF — malware analysis report

Static analysis result for SHA-256 81109e9c64b89853…

MALICIOUS

PDF

174.5 KB Created: 2021-07-13 19:28:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 6a0c77bd1da004fe031b9ff1718f39e3 SHA-1: e21fc850398c9ac470c19ccb4accb469c76e4830 SHA-256: 81109e9c64b8985396e86bb58070cf5ce0861a96901898e70e3541aa91f261cd
164 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It functions as a link farm, directing users to numerous external websites, many of which are hosted on compromised or disposable domains. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM firings indicates a deliberate attempt to obscure the true destination and leverage potentially untrusted hosting. The document body is heavily obfuscated and unreadable, suggesting it is not intended for human consumption but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://luatsutiengtrung.com/app/webroot/uploads/files/rotevakog.pdf In PDF document text
    • https://samarpanbharat.org/trila/userfiles/file/nukufonamirofokut.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/buminevav.pdfIn PDF document text
    • http://ngocvietbungalow.com/upload/files/damifoxebebadeger.pdfIn PDF document text
    • http://markasib.ru/ckfinder/userfiles/files/24243549110.pdfIn PDF document text
    • http://cancercareresearch.com/userfiles/file/65027309588.pdfIn PDF document text
    • http://www.tomasjelinek.com/img/pub/file/netarebiwibusibigatizon.pdfIn PDF document text
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/ba180fc31d29e86f7b5174bbde7e7107/32431319193.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd3bc281732---38120009243.pdfIn PDF document text
    • https://wpsqld.com.au/wp-content/plugins/super-forms/uploads/php/files/1c28b509c6bfde8f412548985e9693ab/wexadebebegowuzosodadari.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608faae42cc94---jamudijigigowip.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608459a2bee3b---dedesogabevurasib.pdfIn PDF document text
    • https://dpt-mh.com/uploads/news/files/79408663645.pdfIn PDF document text
    • https://socialacademy.gr/wp-content/plugins/super-forms/uploads/php/files/af6e10f2fc555c6e1ed9d40c87a5030b/54905959949.pdfIn PDF document text
    • https://www.amiunaorchestra.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b47a487ebb7---9062001818.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/1d899a9220d99994dfff638109566e28/13998038841.pdfIn PDF document text
    • http://atut-biuro.com/uploaded/file/70477397395.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a802c698302---kuzapesemosogupemaziguv.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/dd4bbc40d3312c5e09a3b247be9f288d/bedojojuwitoxef.pdfIn PDF document text
    • http://www.ks-zahnarztpraxis.de/upload/files/10424553049.pdfIn PDF document text
    • http://galettedesrois.hu/userfiles/file/nelajeretarevo.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16080f948286a3---mipedu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=english+10th+text+bookPDF 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_off00024a3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x24A3E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00026250.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x26250 19140 bytes
SHA-256: d4f0678381b6e89c43bfc0709be601db5d9b1222ee1ad4285bc27584352a5fc4
font_02_sfnt_off000294aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x294AA 10616 bytes
SHA-256: 942be1fe11471169488f5ebebcbef417fef4de8893ddc9fc027f61d240d4d71b

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