Malicious PDF — malware analysis report

Static analysis result for SHA-256 f41faf49ae11e917…

MALICIOUS

PDF

93.6 KB Created: 2021-06-27 16:51:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d5d0e81c453a59d4773197b9bafc3b21 SHA-1: b75a61815c4f77edb533b3aecf3a90e205e12d0c SHA-256: f41faf49ae11e91790e7dc9efa62fb451ad02772e39cb145ec89ddedd1bc33c1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to various domains, many of which appear to be compromised WordPress sites used for hosting PDF files. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests these PDFs are part of a link farm designed to manipulate search engine rankings or distribute malicious content. No scripts were extracted, but the presence of multiple external URIs and the 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristic strongly suggest the document's purpose is to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • 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.
  • 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://smidgel.ru/uplcv?utm_term=the+sickness+is+not+unto+death
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/fda3bad49326c735146d183ec2264802/jowogibekipuzenonasuwar.pdf
    • http://footstepfloor.com/upfiles/files/jufukodabevewobimamibafe.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/948116ffcf71f489e239065c7ebda741/zupowodakofibavasuwovet.pdf
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2a9663ef0d---puluwudopujatafigum.pdf
    • http://rehahomecare.com/upload/editor/files/fopofipif.pdf
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/sj8u04b514lf69dpg8uq4c68a2/vijonururezusuxinak.pdf
    • http://chandigarhdatarecovery.com/files/file/94159420984.pdf
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092d73c3e9f2---vezepetitajutojosaladuver.pdf
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/h84gl5jou6e5qt8aba06mdiqh1/35039438672.pdf
    • http://wmehoa.org/clients/d/df/dff1b85474dadb967ea0c40f6d5e37f8/File/4532708445.pdf
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/0e605c9386479d754d7d034c0c669989/dobowenapipapururudu.pdf
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/6e02eb6c33313aba8496bcc4e438fec0/89001592327.pdf
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/fe3099f994f14fe97a04be84823d8622/lowefepidoneli.pdf
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081c11cb3e1b---nudixujokemomerat.pdf
    • http://www.kizkulesikizogrenciyurdu.com/public/ckfinderuploads/files/fukofajega.pdf
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/01a8c0ba370cc90a368faa23709e338c/30595471064.pdf
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a40209981da---dorovekadamizozo.pdf
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/8e1b0eaiemjfi7ndi759t0mglj/72491080613.pdf
    • http://www.gonouvellezelande.com/files/tokugededovorotasa.pdf
    • http://camwater.org/media/files/37874171119.pdf
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/aa807c6ec2c78044bcfd3db880ee4e50/16015985973.pdf
    • https://ensasoft.com.tr/wp-content/plugins/super-forms/uploads/php/files/fspq0atobklkdqb12g9ernn8df/xidobulutamopabevufage.pdf
    • http://gentlemensquartersbarbershop.com/wp-content/plugins/super-forms/uploads/php/files/40c6b47a32e2bf8e66141cb12481197c/26273863627.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010ee7.bin
cc0d42a59f155d33235c7488f0065a374cacb0cd65b3cd95aff41ea8eef24cad
pdf-font-stream PDF embedded font (sfnt) at offset 0x10EE7 16428 bytes
font_01_sfnt_off00013960.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13960 16792 bytes
font_02_sfnt_off00015177.bin
0aec59e621f413f2849de55ef0967a2468760f7150a574b6f8036968498c3013
pdf-font-stream PDF embedded font (sfnt) at offset 0x15177 10476 bytes