Malicious PDF — malware analysis report

Static analysis result for SHA-256 c831a697bd893620…

MALICIOUS

PDF

84.9 KB Created: 2021-09-23 08:56:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: e549e00b0223828a6b87f2918e03c1ac SHA-1: 1cb1377daa40ae840feb21433be9900e1372c6d7 SHA-256: c831a697bd89362003ae5706525518778e90ae7f11f34c385e4a95b78ffe72ca
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs pointing to various domains, many of which are structured as link farms. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to create a large number of links on disposable hosting, a common tactic for phishing or distributing malicious content. No scripts were extracted, but the presence of many external URIs suggests the primary attack vector is directing users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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.
  • 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://huntic.ru/uplcv?utm_term=class+of+the+titans+cast PDF link annotation
    • https://arnetbilgisayar.com/upload/ckfinder/files/dabutabobijomaroz.pdfIn PDF document text
    • https://andhimazhai.com/images/files/nuputapukuder.pdfIn PDF document text
    • http://salt17.com/userfiles/files/sudiguru.pdfIn PDF document text
    • http://joltiy.ru/uploads/files/31131078929.pdfIn PDF document text
    • http://mashhadgardi724.ir/basefile/mashhadgardi724/files/53588122797.pdfIn PDF document text
    • http://veterinariogiardinelli.it/userfiles/files/jikapuwuzaxuju.pdfIn PDF document text
    • http://outspokenholland.com/userfiles/fckFile/20210923132204.pdfIn PDF document text
    • http://alpinist.store/sribati/editor/uploadfiles/zijukez.pdfIn PDF document text
    • http://kuresi-kaitori.com/upload/content_pic/files/vopiwovevinetuxepiwirideb.pdfIn PDF document text
    • https://bya-ingenieria.com/ckfinder/userfiles/files/morupusefofukan.pdfIn PDF document text
    • http://hooleihomes.com/cms_images/file/lenul.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613530ebee196---vagagedirisegitojovas.pdfIn PDF document text
    • http://bighost.vn/uploads/userfiles/file/78485814140.pdfIn PDF document text
    • http://aquatherm-graz.at/files/nutasetasetukikobekifa.pdfIn PDF document text
    • http://sinching.com/uploadpic/files/202109180436464497.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/55c40vu3uhbb8ao1f57j98qomk/27241884143.pdfIn PDF document text
    • https://exihomes.com/userfiles/files/39228189079.pdfIn PDF document text
    • http://cana.vn/uploads/userfiles/file/30799282707.pdfIn PDF document text
    • http://videotour24.com/data/fckupload/file/guponexefodure.pdfIn PDF document text
    • http://business-baltic.com/myfiles/dok/fogelepi.pdfIn PDF document text
    • https://ristovski.mk/public_html/upload/userfiles/file/lomenidofejufavaxinasugi.pdfIn PDF document text
    • http://kondicionery-noginsk.ru/upload_picture/file/8875325010.pdfIn PDF document text
    • https://quimicasorocolor.com.ve/ckfinder/userfiles/files/bolajoj.pdfIn PDF document text
    • http://delannahotel.com/user_img/file/3063646333.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_off0000e5ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fdfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDFC 18844 bytes
SHA-256: 2c50110e1f1a433f6c2d187d8616fd4bc01356f8204036ba5e8a98e3f94b647a
font_02_sfnt_off00012e67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E67 10364 bytes
SHA-256: c4619174f77ee63b0f773a83ad0ad6bfbf716c7862d0fcb3f0309670301ba20a