Malicious PDF — malware analysis report

Static analysis result for SHA-256 12837a6c6956dc77…

MALICIOUS

PDF

81.6 KB Created: 2021-09-08 06:03:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 2865f7f5920dfbeb868f0f50e97c4364 SHA-1: 5fd77fc799d84622a8df4d59b9aaecbb744dce51 SHA-256: 12837a6c6956dc7741cbb8157b1d0e4865f6e9692836feb008f1d369cf2b3a28
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to numerous external PDF files hosted on various websites, many of which appear to be compromised or disposable. This technique is often used for SEO poisoning or to distribute further malicious content. The ML classifier strongly indicated maliciousness, and the presence of multiple links to potentially compromised CMS uploads supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • 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 http://naphogacomposite.com/upload/files/20298830503.pdf In PDF document text
    • http://onlinepravenconsultant.com/uploads/wysiwyg/files/bunawidojisafudanezalopu.pdfIn PDF document text
    • https://www.perfumista.co.uk/wp-content/plugins/super-forms/uploads/php/files/791acadc0a234e96cf99411c0f10b35d/2395372377.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/1b0fcf75074a7fc0b390154e2f97976f/lazopunedenetijetidije.pdfIn PDF document text
    • http://kavtas.com/images_upload/files/zakowa.pdfIn PDF document text
    • http://alptw.com/images/files/mexorelez.pdfIn PDF document text
    • https://thegioibaobicarton.com/Images_upload/files/vifewowudedutazope.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd25cf84e88---kapokaso.pdfIn PDF document text
    • http://yossy.biz/userfiles/file/59933046011.pdfIn PDF document text
    • https://www.kalirich.com/wp-content/plugins/super-forms/uploads/php/files/jfkbckt57q8n99jo1t5ukbbqp3/tobisisufevifu.pdfIn PDF document text
    • http://azbuka-d.ru/ckfinder/userfiles/files/7211595064.pdfIn PDF document text
    • https://tessuno.com/upload/files/612d32c239a57.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/3gm66o5850p2f2pb6426k11v17/72391929501.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606fbad84b816---tamajanurote.pdfIn PDF document text
    • https://elesud.it/img_pagine/file/39325429643.pdfIn PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/79c1b1a8e0badee390a5f9d345b26966/popawanuvakiwivibam.pdfIn PDF document text
    • https://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/up9hio3i3sro3boju3u87du6u0/94981144514.pdfIn PDF document text
    • http://france-ex.com/images/blog//file/9170771023.pdfIn PDF document text
    • http://olsztyntransportmedyczny.pl/userfiles/file/dukuvenefubirikewela.pdfIn PDF document text
    • http://fqcycpa.com/jingkelun/userfiles/files/20210621202956.pdfIn PDF document text
    • http://xn--clinicaquirogavilario-vbc.com/wp-content/plugins/super-forms/uploads/php/files/7n5pdl6n8se9io37lcrirndmn2/riwiludijewebizuzena.pdfIn PDF document text
    • http://tuttotop.com/userfiles/files/38773157302.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=retardasi+mental+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_off0000dc97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC97 10584 bytes
SHA-256: cb0ce5bb75c9928c90917d12e75d628c4b7c1adda0c273fbdf961fc6e2974164
font_01_sfnt_off0000f4a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4A5 17048 bytes
SHA-256: b95abb20737b9c24280329b7b314a206da213c4b8864984b48be424faf15781a
font_02_sfnt_off00012096.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12096 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1