Malicious PDF — malware analysis report

Static analysis result for SHA-256 da4df337184c9a87…

MALICIOUS

PDF

79.3 KB Created: 2021-09-10 12:31:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7821b40d080e85c8750b00705c755a62 SHA-1: c358d812b3212f693a1f85a619a5715118d4342d SHA-256: da4df337184c9a876fdb904b78617d4f52e590fe9938aa452dadd674e51ead11
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by a ML classifier and ClamAV, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous external URIs, many of which point to a link farm structure. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests the PDF is designed to redirect users to a network of sites, likely for SEO poisoning or to host further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.tvmreza.tv/ckfinder/userfiles/files/dokalaripuveba.pdf In PDF document text
    • http://longbienco.com/js/ckfinder/userfiles/files/35049561521.pdfIn PDF document text
    • http://algarestofos.pnh.pt/js/ckfinder/userfiles/files/85734262897.pdfIn PDF document text
    • http://gintaras.cz/userfiles/file/1133985243.pdfIn PDF document text
    • https://budgetparking.ca/admin/uploads/file/14581998528.pdfIn PDF document text
    • http://gaytonfa.com/upload/files/7775879217.pdfIn PDF document text
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/161370a5d569b5---jisejelevasat.pdfIn PDF document text
    • https://pastijptoto.com/contents/files/lilotewezom.pdfIn PDF document text
    • http://sensitiva.fi/UserFiles/File/65019575126.pdfIn PDF document text
    • http://villkasz.hu/editor_up/45171663694.pdfIn PDF document text
    • http://gnatowski.pl/attachments/file/69790423685.pdfIn PDF document text
    • https://efficimm.fr/userfiles/files/zugalavarawixofovidemo.pdfIn PDF document text
    • https://airin.lv/images/userfiles/file/43051062081.pdfIn PDF document text
    • http://kondicionery-vidnoe.ru/upload_picture/file/zakimigitisulizapumat.pdfIn PDF document text
    • https://kalyna.ua/sites/default/files/userfiles/file/zoxinepulazujovumi.pdfIn PDF document text
    • https://regenerateacademy.com/file/3577019995.pdfIn PDF document text
    • https://preciseenergygroup.com/media/nadiwufiwej.pdfIn PDF document text
    • http://hotelpenza58.ru/ckfinder/userfiles/files/pegotexo.pdfIn PDF document text
    • http://villa-margherita.biz/userfiles/files/xawekixezemilitelugowefib.pdfIn PDF document text
    • https://xn--hjrnskadeakademien-mtb.se/userfiles/file/mejukanuxuzezirivu.pdfIn PDF document text
    • https://balbok.net/admin/ckfinder/userfiles/files/fojelijezetusilezal.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/e650d7b7b0e58906cbc9b86345bd2c70/jitij.pdfIn PDF document text
    • http://newo.ru/files/files/19614984471.pdfIn PDF document text
    • http://www.smpnuenen.nl/images/files/98913731681.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=explode+arena+for+android+free+downloadPDF 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_off0000ca73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA73 10396 bytes
SHA-256: 245ecbfef41326aa2061d25489982f1afc1890efbeb633c558cd8b29852b34eb
font_01_sfnt_off0000e20f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE20F 19624 bytes
SHA-256: 75762ea4d3d9c37cdcf0087fa15feba86f8dd5c1168b6ed7895ac72634cb6989
font_02_sfnt_off0001155e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1155E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1