Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc36dd9be82d6bfa…

MALICIOUS

PDF

82.2 KB Created: 2021-09-20 17:06:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 275d4da6647cbd1f5ef9ebcebf31fb79 SHA-1: 3a789380097f19fb1dd869b3e103382ad0a71cf3 SHA-256: dc36dd9be82d6bfa1d417b0ea66660c6c88388792d0493635e0b5497b10bcd64
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs pointing to various domains, many of which are associated with link farms and compromised CMS uploads, suggesting a phishing or malware distribution scheme. The PDF structure and embedded content indicate it's designed to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://catamma.ru/uplcv?utm_term=mx+player+format PDF link annotation
    • http://sb-78.ru/files/file/lapepodijedozurinanimo.pdfIn PDF document text
    • http://studiocinti.eu/userfiles/files/dujomazen.pdfIn PDF document text
    • https://mimpiindahsatu.com/contents/files/popesebulijuruvabiwatawa.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16146576d39d99---xapipug.pdfIn PDF document text
    • http://hysansam.com/fckeditor/userfiles/image/fogivojokuzidosovates.pdfIn PDF document text
    • http://mathrainbow.com/userfiles/file/39608877158.pdfIn PDF document text
    • https://tonymusic.se/UserFiles/files/948524226.pdfIn PDF document text
    • http://gruppocreta.com/userfiles/files/budoj.pdfIn PDF document text
    • https://rafaellopezehijo.com/upload/files/83275812926.pdfIn PDF document text
    • http://jl-vacuum.com/upload/files/47549787277.pdfIn PDF document text
    • https://stalbeckers.nl/userfiles/image/file/jizanisevixivodef.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/86403283640.pdfIn PDF document text
    • https://oncetrabzon.com/resimler/files/57995670491.pdfIn PDF document text
    • https://shipnhanh247.vn/asset/files/dukufisakelubu.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16136cec32c36d---82731926956.pdfIn PDF document text
    • http://elskup.pl/images/assets/file/wiporafagorugiroz.pdfIn PDF document text
    • http://dainindo.com/Uploads/userfiles/files/46375961196.pdfIn PDF document text
    • https://aksusu.com/upload/files/taxekokefigodemasef.pdfIn PDF document text
    • https://chaletsuenodesol.de/files/rifebejikikepubov.pdfIn PDF document text
    • https://getlovebooks.com/wp-content/plugins/super-forms/uploads/php/files/527295f313d25c702c395ad3b04d073a/lekefopidubusav.pdfIn PDF document text
    • http://optimumnieruchomosci.pl/uploads/userfiles/files/84436628873.pdfIn PDF document text
    • http://tofuyatogo.com/uploads/files/ginezosokufarefasogo.pdfIn PDF document text
    • https://webmakler.org/userfiles/file/kimewudubopuwepivuwuli.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_off0000de32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE32 17672 bytes
SHA-256: 966484e58d2a5c2b818c34417c6ce55a8f2b47a6563ab7547d0ab9e1fddb7a25
font_01_sfnt_off00010c0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C0E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012425.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12425 10364 bytes
SHA-256: e72899450e3d3970fce5a97d0f260bf1ca8228fc3db6b24a6652a6f33d37816e