Malicious PDF — malware analysis report

Static analysis result for SHA-256 3bb6c0358804b911…

MALICIOUS

PDF

81.6 KB Created: 2021-09-18 07:32:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b91dfbd37c9b9c430a84ac441df48035 SHA-1: 0a59b70599df2848c46ecc88073c318d9f7a1acc SHA-256: 3bb6c0358804b911d3fe308b867bb8e8eaf0c66b60071b2dd78ea213475a5fdd
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript, which is often used to redirect users to malicious websites or exploit vulnerabilities. The heuristics indicate a link farm structure, with numerous URLs pointing to various domains, some of which are hosted on compromised CMS uploads. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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.
  • 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://wastran.ru/uplcv?utm_term=free+download+android+emulator+for+windows+7+32+bit PDF link annotation
    • http://topmebli.com/content/xuploadimages/file/49836375612.pdfIn PDF document text
    • https://martensmgt.com/business_school/uploads/file/15032445335.pdfIn PDF document text
    • http://mim2010.ru/userfiles/file/movajatinixupur.pdfIn PDF document text
    • http://myucmas.com/userfiles/file/kutulofivizonobirolalofes.pdfIn PDF document text
    • http://jeansresource.com/js/ckfinder/userfiles/files/98564879489.pdfIn PDF document text
    • http://thaicockstar.com/ckfinder/userfiles/files/99689481058.pdfIn PDF document text
    • http://namuvaldymas.lt/userfiles/file/nowirurimozaporokozikud.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/4f3237a9b48953606319c5d61044dd9b/kuwimomorijufafaduti.pdfIn PDF document text
    • http://3q1p.com/upload/file/210902053458699501b88n38m77gja.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/nokiturinowipat.pdfIn PDF document text
    • http://geometracosentino.com/userfiles/files/nedezukenofefivijunuse.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ca198e3570---61900329890.pdfIn PDF document text
    • http://www.benyowsky.com/resources/files/sujixifedariro.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/065d00c1c5f1f5c918c85b67ae18ff6d/bixekinalakuwomagom.pdfIn PDF document text
    • http://vaynhe.com/upload/files/tawukemadibepifewur.pdfIn PDF document text
    • http://caythuocdangian.net/images/files/46715857133.pdfIn PDF document text
    • http://nguoigiupviec99.com/webroot/img/files/zuluvubevenegonirox.pdfIn PDF document text
    • http://inkjetartandimage.com/Uploads/file/genagi.pdfIn PDF document text
    • http://a899.net/userfiles/file/14777033426.pdfIn PDF document text
    • http://studiosantese.eu/userfiles/files/mijijoxefa.pdfIn PDF document text
    • https://gsacademy.ge/uploads/files/3492811981.pdfIn PDF document text
    • https://raiporjai.com/piceditor/file/wujetakowuref.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_off0000d835.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD835 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f04c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF04C 11160 bytes
SHA-256: c011d6bcc228dcea76ebdce02e7c598e34d38a2b1e78eaf2a55a0cbe688327ad
font_02_sfnt_off00010a89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A89 17492 bytes
SHA-256: b4963d90925ca66829e679249583045574eb06efc94b680334d2f4bec1e629d3