Malicious PDF — malware analysis report

Static analysis result for SHA-256 838cfaf304531c8b…

MALICIOUS

PDF

84.3 KB Created: 2021-09-09 06:11:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d00bfd686a65077e95b796007a705bff SHA-1: baf510c72935549d7c71b712752c44c7ffc777b5 SHA-256: 838cfaf304531c8b5fc45f202397e0ecc53d6efc0bf649eaf434b9740743a399
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, many of which point to external websites, suggesting a phishing or malware distribution attempt. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a large number of links spread across disposable hosting, further supporting this. ClamAV detection as 'Pdf.Phishing.Trojan' and ML classification confirm the malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://cructi.ru/uplcv?utm_term=statistics+bell+curve+standard+deviation PDF link annotation
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/16132e0195aa7e---17724354918.pdfIn PDF document text
    • http://vansuloi.com/uploads/userfiles/file/24798357824.pdfIn PDF document text
    • http://thediamangroup.com/_images/files/wajav.pdfIn PDF document text
    • https://y3stwk65l-mn9.com/contents/files/16016176666.pdfIn PDF document text
    • http://keyflounge.nl/userfiles/file/seduzupagajo.pdfIn PDF document text
    • http://ambulatorioveterinariocigliano.com/userfiles/files/86162587065.pdfIn PDF document text
    • https://autopsrus.aerovents.com/ckfinder/userfiles/files/39234960026.pdfIn PDF document text
    • http://itaxabc.com/userfiles/file/20210903000239_24520735.pdfIn PDF document text
    • https://alzubidi.com/userfiles/files/pepefusixofilami.pdfIn PDF document text
    • http://www.hz-kontejnery.cz/ckfinder/userfiles/files/xatosuduba.pdfIn PDF document text
    • https://kaptenhoki.net/contents/files/45103745985.pdfIn PDF document text
    • https://tybistanbul.org/resimler/files/gejofavujekidanex.pdfIn PDF document text
    • http://cleanking.net/userData/board/file/xijagozumo.pdfIn PDF document text
    • http://olympusflights.com/files/files/39518535770.pdfIn PDF document text
    • http://moje-stranky.eu/userfiles/file/98257186356.pdfIn PDF document text
    • http://nissanotogovap.net/uploads/images/files/49467755425.pdfIn PDF document text
    • https://cmoretv.com/userfiles/bixijorojenetosokuz.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16138d09f70265---jivoladugomo.pdfIn PDF document text
    • https://kltccompany.com/ckfinder/userfiles/files/81754354187.pdfIn PDF document text
    • https://akproauto.com/nbloom/fckuploads/file/bapumadupa.pdfIn PDF document text
    • http://www.tsahimmongol.com/uploads/images/files/zawimu.pdfIn PDF document text
    • https://dubaimotorcycletours.dubaimotorhomerentals.com/uploaded_images/files/rujozidemizeranelubedira.pdfIn PDF document text
    • https://fancybox.pamlskovnik.cz/ckfinder/userfiles/files/59504158490.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_off0000e1db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1DB 18488 bytes
SHA-256: df0610758efc717265ab3ed931c193a6364ca1bae4b4d956d0943826818f744e
font_01_sfnt_off00011271.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11271 10744 bytes
SHA-256: 32dc0c49b80164e6ed1def0907de9812f3dc242ddc6b6c5cf243402290c29497
font_02_sfnt_off00012b41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B41 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1