Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b6ee8b83739f7be…

MALICIOUS

PDF

88.1 KB Created: 2021-07-31 17:17:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 32f764aafc848ef2ec47a39ae4c84301 SHA-1: 21571753a3bde1742c4714a02aacb6bd2a077eca SHA-256: 4b6ee8b83739f7be926c50b642fd54915491dfbf820e752b0b914ddec5bdeb13
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, presenting numerous external URIs that point to various websites, some of which are hosted on compromised WordPress installations. The primary purpose appears to be directing users to potentially harmful content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://krisoc.ru/uplcv?utm_term=how+to+install+busybox+on+rooted+android+phone PDF link annotation
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/18ac5952d7d52902166f27739cf88a02/2831838086.pdfIn PDF document text
    • http://bachova-terapia.sk/images/file/mamirufafivogaremafufajog.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/ddca7d9b5a159feeb6f65552e2fcd23c/daliviviwumafalifetezux.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607987e415f8e---35795905200.pdfIn PDF document text
    • https://roc.mn/uploads/files/85300840177.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c3c08cb3af---84661437656.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16075610fd643d---xoribipovusedoli.pdfIn PDF document text
    • https://valserve.in/web/k/main_admin/ckfinder/userfiles/files/buwuvukodotalijoxa.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a621cdc1790---9080844762.pdfIn PDF document text
    • https://albawadiroad.com/userfiles/files/lebadapitosadovogo.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160812136c4a32---2868448228.pdfIn PDF document text
    • http://capmar.eu/userfiles/file/jibinolurafikujunisuk.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160fd5ed5d7fa2---rizelurenulom.pdfIn PDF document text
    • http://cuboni.com/uploadfile/hong202107250342079351.pdfIn PDF document text
    • http://ck-tct.ru/userfiles/file/80655089281.pdfIn PDF document text
    • http://birnagarcollege.in/userfiles/file/11583642443.pdfIn PDF document text
    • http://dtcguild.org/clients/80367/File/woletekiruzoworonaku.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/t6q21866qgi5o1uko6vte02efj/pepunosiwabevafeminowud.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/a2ab5e60e161c8d26d1e2ade8aa12a95/63340057460.pdfIn PDF document text
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/a8fhie2vfn1fs3btfoqvejmedi/tadirepidebefave.pdfIn PDF document text
    • http://jevades.com/aircraft/fckimages/file/98844410676.pdfIn PDF document text
    • https://roeveragri.ac.in/wp-content/plugins/super-forms/uploads/php/files/ae29622cd819d75a183ad103a0d10f7d/89395897616.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/47666547701.pdfIn PDF document text
    • http://kup-vino.cz/web/ckfinder/userfiles/files/90958032884.pdfIn PDF document text
    • https://shotclock.ca/wp-content/plugins/super-forms/uploads/php/files/11f18f7f0a8833fe6c2e91c5523fa1f4/37002868771.pdfIn PDF document text
    • http://lnimeina.it/userfiles/files/ximupesi.pdfIn PDF document text
    • https://brandonsmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/nkcbi7ev4o9n8oa3ve0qq2sv74/77038684286.pdfIn 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://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_off0000f468.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF468 11024 bytes
SHA-256: 7dcb57a5720e977c795afce47a068789b5f81324a84f02a6b46d4639b982aa8b
font_01_sfnt_off00010dc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DC8 16936 bytes
SHA-256: 20b9cf75147792fbf6484d38c016200d9ca69789356f80958d312f5f6ca34f99
font_02_sfnt_off00013998.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13998 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1