Malicious PDF — malware analysis report

Static analysis result for SHA-256 635175f333fa40f4…

MALICIOUS

PDF

75.6 KB Created: 2021-09-16 10:59:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: daaf4912c6a2ebb3f84e60c8f1cb55a7 SHA-1: 7e6decf4d12f097ec44f25ed4e2b11f291551c1e SHA-256: 635175f333fa40f4d37f2c0a1c3872c81e6413646beaaab934bfd3fa2c5d3cdf
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains an embedded JavaScript stream and a large number of external URIs, many of which point to potentially compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest a link farm or SEO poisoning attack. The embedded JavaScript likely facilitates the redirection to these malicious links, contributing to a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • 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 http://nasledie-sluck.by/var/upload/file/kugogiguvur.pdf In PDF document text
    • http://tsnpharma.com/upload/files/parabeninafijuwadetibukar.pdfIn PDF document text
    • https://futuresbuilder.net/dayafter/uploadimages/newsimages/file/silijewupebawelitito.pdfIn PDF document text
    • https://szabolcsipeter.com/userfiles/file/15005477799.pdfIn PDF document text
    • http://baove24h.info/upload/files/balubukabinafed.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a5dbc31f08---9237899426.pdfIn PDF document text
    • http://wacommerce.net/home/integrity/public_html/ckfinder/userfiles/files/25244547805.pdfIn PDF document text
    • http://everbeenmagnet.com/js/upfiles/files/dawasaxomojexite.pdfIn PDF document text
    • http://karaokejdi.com/ckfinder/core/connector/php/upload/files/47441662395.pdfIn PDF document text
    • http://faisaltowel.com/survey/userfiles/files/nofemuligimapidororim.pdfIn PDF document text
    • http://snailgame.ru/upload/files/20210914101521.pdfIn PDF document text
    • http://saluteebenesseresas.it/userfiles/files/39653771402.pdfIn PDF document text
    • http://back2wood.de/userfiles/file/pewav.pdfIn PDF document text
    • https://nyirfa.hu/uploads/files/fizekodesijafewoxe.pdfIn PDF document text
    • https://theelementrama9.com/userfiles/files/zutaluzufovojigud.pdfIn PDF document text
    • http://esrafisek.com/images_upload/files/lowelotubusawigujelulos.pdfIn PDF document text
    • https://tanthueviet.vn/img_data/files/topifavunuzekotumaw.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/16138324c90c0a---medipiv.pdfIn PDF document text
    • https://leonardscopysystems.com/home/leonards/public_html/ckfinder/userfiles/files/zetoxakimarenofitajaxov.pdfIn PDF document text
    • https://glaskunstcentrum.nl/images/file/99362993063.pdfIn PDF document text
    • http://tensoinox.com/userfiles/files/85581590922.pdfIn PDF document text
    • http://fujavietnam.com/images/Download/22666871443.pdfIn PDF document text
    • http://agro-pasz.pl/ckfinder/userfiles/files/20313597748.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/7nteaeh6742seacmvf52k77cc5/gisesodijagefew.pdfIn PDF document text
    • https://akproauto.net/nbloom/fckuploads/file/bokuwaxebuduvevoze.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=watch+quiet+place+2+full+movie+freePDF 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_off0000c247.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC247 17164 bytes
SHA-256: 8fc235af1cdb7bc725024b2460e055acc89ef5d37b87fa7ba013d39c969dd13e
font_01_sfnt_off0000eec8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEC8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000106df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106DF 10896 bytes
SHA-256: 762230fc80cf2ce09f6c512cd1caaaea500f4b4731c8542a6bda257b4d0972e6