Malicious PDF — malware analysis report

Static analysis result for SHA-256 9ca5bb8dfb316158…

MALICIOUS

PDF

86.8 KB Created: 2021-09-23 00:19:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 03e847af845c2ccea29e9e31f5fb228f SHA-1: 0e9987dea2dd2238b9d7f982fe6354c76184378a SHA-256: 9ca5bb8dfb316158661739d4ce01b8062695061f88d57d979ee01580a86e08d2
206 Risk Score

Malware Insights

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

The sample is a PDF document that exhibits characteristics of a phishing lure, specifically by presenting a fake CAPTCHA to trick the user. It contains numerous links to external PDF files hosted on various domains, suggesting a link farm or downloader infrastructure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to deliver a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 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.
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • 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://queure.ru/uplcv?utm_term=roadrunner+email+server+settings+android PDF link annotation
    • https://marosme.ro/hirek/file/7578068340.pdfIn PDF document text
    • https://websbag.com/uploads/files/31218121102.pdfIn PDF document text
    • http://anapro.com/ckfinder/userfiles/files/14193640555.pdfIn PDF document text
    • http://sswjeans.com/files/51093557128.pdfIn PDF document text
    • https://avukatwebsitesi.kocgrafik.net/upload/files/puxevumusixiwapitajefi.pdfIn PDF document text
    • http://yotlist.com/uniformkontakt/userfiles/image/files/munofatoturafu.pdfIn PDF document text
    • https://traiteur-troyes-mariage-buffet-aube-10.blaisot-traiteur.fr/ckfinder/userfiles/files/rasivexukozidoborapim.pdfIn PDF document text
    • http://gpe-el.pro/ckfinder/userfiles/files/buvebot.pdfIn PDF document text
    • https://www.artikel238.nl/emmwebbit/resources/ckfinder/userfiles/files/jopejisereguxut.pdfIn PDF document text
    • http://karaokejdi.com/ckfinder/core/connector/php/upload/files/70191323079.pdfIn PDF document text
    • https://twr1115.net/files/fckeditor/file/59718622414.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1614907d7cbb0a---42298758615.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/dhi38memqk9sevq3r6t8s55i16/29960073801.pdfIn PDF document text
    • http://inbiosa.eu/static/cfiles/files/589213415.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/36bc791cbac3447c11442d89ff767d42/powagakepekudegofibij.pdfIn PDF document text
    • https://prestinieurope.ch/userfiles/files/dugugeverafezukabujas.pdfIn PDF document text
    • http://sacmacbook.net/userfiles/file/9329276616.pdfIn PDF document text
    • http://thietbiantoanttk.com/uploads/files/wixewuwomotu.pdfIn PDF document text
    • https://strongpointmarketing.net/userfiles/file/31358691018.pdfIn PDF document text
    • http://lucidarepavimentimarmogenovaealessandria.it/userfiles/files/37020871643.pdfIn PDF document text
    • http://svenskafik.se/uploads/fckeditor/file/88220942367.pdfIn PDF document text
    • https://maggievanostrand.com/uploads/media/file/dikejemedimeduviw.pdfIn PDF document text
    • http://dfwarbitrator.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/1270814947.pdfIn PDF document text
    • http://ayhancevik.com/images_upload/files/38391030392.pdfIn PDF document text
    • http://101balkon.ru/upload/files/82304905804.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_off0000ed5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED5C 10800 bytes
SHA-256: 68e7e451c19df3e4783be53613987dee76d6e398b35bcce76bac61a9ea6fec9e
font_01_sfnt_off0001060d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1060D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E1F 18384 bytes
SHA-256: fbfe17e639de1bf0c6d344f3bcbec437b8d38092801fc8cd192c0cf2b16f2654