Malicious PDF — malware analysis report

Static analysis result for SHA-256 cdb6db0a34959697…

MALICIOUS

PDF

82.0 KB Created: 2021-09-05 09:11:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: ea50d0f28ceba89e89593ff8aa633fb6 SHA-1: 90955ae514a78af6bde8a3b00e5ac769f2cce090 SHA-256: cdb6db0a3495969793ffed566483df6523cad8c01d2d07d333535c18140badeb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by multiple heuristics as a link farm, with many URLs pointing to compromised WordPress upload directories. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing trojan. The document's structure and embedded URLs suggest an attempt to redirect users to potentially harmful content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • 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.
  • 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.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087b836c7f93---rebegozaruvowokifawu.pdf In PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0b76d64e59---migarilowuposadit.pdfIn PDF document text
    • https://store-connector.com/_upload_bilder/_filemanager/file/dinogizapinidixerij.pdfIn PDF document text
    • https://marljivo.hr/userfiles/file/7744344023.pdfIn PDF document text
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/ee5f60fb00a6652c8040e00133956778/64790972514.pdfIn PDF document text
    • http://www.anclupnapoli.it/userfiles/file/puwodunojaturavajotaj.pdfIn PDF document text
    • http://nessium.net/userfiles/file/lumutimisatudu.pdfIn PDF document text
    • http://autodilykanka.cz/cmsimple/images/file/jawimutapafixaroboponi.pdfIn PDF document text
    • https://sakkestadbil.no/userfiles/file/66829206302.pdfIn PDF document text
    • https://e-lightingcontrols.com/wp-content/plugins/super-forms/uploads/php/files/415b32b12a879ac98c77d0d9d50a1ebe/digubuwuvelo.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/88296c668e1dbc1db3cb397db05fbab3/lomiruterobuxamimunas.pdfIn PDF document text
    • https://vinasimex.com/uploads/file/xopidenuwurogop.pdfIn PDF document text
    • https://sharadsangam.org/UserFilesTwo/file/73983116916.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/4539155804.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba6bb885653---64262373383.pdfIn PDF document text
    • http://syuncyoku.jp/upload/file/15808879221.pdfIn PDF document text
    • http://thebankcardservices.com/uploads/files/dotejobekupubemewo.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ddce8d79ecd---dikudane.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609e01af81d10---fidanazujurudirixan.pdfIn PDF document text
    • http://tid.vn/upload/files/64336314198.pdfIn PDF document text
    • http://realcomfort.ru/content/upload/file/66133083087.pdfIn PDF document text
    • https://noithatkuongthinh.com/uploads/files/93616293750.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=six+sigma+yellow+belt+book+pdfPDF 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_off0000d8e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8E6 11248 bytes
SHA-256: e2adebfb790db62e0ed3d653883f4c86c42eeb85555e0e97e276a1f0af8a4b5b
font_01_sfnt_off0000f2f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2F7 18192 bytes
SHA-256: bde985d9900b97975c95174a865395c98ef40179d856be3c20b19304ebd3d95d
font_02_sfnt_off00012241.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12241 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1