Malicious PDF — malware analysis report

Static analysis result for SHA-256 639fba2b160898bb…

MALICIOUS

PDF

89.3 KB Created: 2021-09-03 22:00:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-02
MD5: a67ea22fa63656dbd571bea3d2564b9c SHA-1: cdb3155cc40577315b5b637cdd108972635bb7a1 SHA-256: 639fba2b160898bb7116282e95b277e1be1efcde54620fc8c668404c10f36018
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://pistant.ru/uplcv?utm_term=lominger+competency+framework+pdf PDF link annotation
    • http://analogsys.com/uploaded/file/559318366089a44561a9e.pdfIn PDF document text
    • http://alompar.hu/uploads/content_files/files/2031220245.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/efov61e7qbkij85125atc4t73o/xuxuxega.pdfIn PDF document text
    • https://shiphangnhanh.net/uploads/image/files/81122333914.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/161148a8bb6fbe---vuxafewadizu.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609b55e9bfbcc---vadadufe.pdfIn PDF document text
    • http://gpmpoolandspa.com/ckfinder/userfiles/files/jaxalojusodifobotip.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074838497a24---8361725932.pdfIn PDF document text
    • http://businessplan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/25226615500.pdfIn PDF document text
    • http://indigobaby.eu/upload/files/temalenomud.pdfIn PDF document text
    • https://aiaciran.org/cache/fck_files/file/90679096082.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6df250333c---bunamubesowafo.pdfIn PDF document text
    • http://graylegalservices.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/80969357003.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/1cvgntoe5ehcpf6dcik9nn4su0/56524647404.pdfIn PDF document text
    • http://dongxuyen.org/upload/files/rimas.pdfIn PDF document text
    • https://crossfitbeeshark.ro/app/webroot/files/userfiles/files/dulasodugenigabexagido.pdfIn PDF document text
    • http://abwmercury.com/uploads/files/gerizulufinofisajirowe.pdfIn PDF document text
    • http://ledson.ru/upload_picture/47212194328.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/be03c1cf2a0de1b7e97fe35fb22e9323/femas.pdfIn PDF document text
    • https://tractorpulling-emmeloord.nl/upload/file/82019021645.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/6cc3cc89d22e27d3d0e9aee6ec8bf5c0/35664357331.pdfIn PDF document text
    • http://www.melloecastro.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074200118f5e---13788014400.pdfIn PDF document text
    • http://ecohouse-lab.com/userfiles/file/puxunizugusu.pdfIn PDF document text
    • http://dobrasekacka.cz/userfiles/file/jokijimemekasekivuvojexox.pdfIn PDF document text
    • https://smartcrm.cloud/upload/files/zigebasebunijobumokixaxu.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_off0000f9f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9F9 10996 bytes
SHA-256: b246144a8b95e7c0de8820a0c79c0d929210ad416d1733ac2104c5b9400aacf3
font_01_sfnt_off0001135f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1135F 16888 bytes
SHA-256: 265f0efe65c269bb76c4f7aed7c0c3986168fdde765a9d033a68f42382002aea
font_02_sfnt_off00013f20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F20 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1