Malicious PDF — malware analysis report

Static analysis result for SHA-256 de4d8d6bbb4d0406…

MALICIOUS

PDF

99.1 KB Created: 2021-06-28 15:16:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 59d4f0a7b0a909d3e66858e0f92835e4 SHA-1: 8cc2a21dea29ae09d156e8b2d793b57ed76112bb SHA-256: de4d8d6bbb4d0406532aec78d4b0ee72dd05d0655a2d929bd722bd1ccfe08fd2
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of external links, many of which point to compromised WordPress installations or disposable hosting. This suggests the document is part of a link farm or phishing campaign designed to redirect users to malicious websites. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 7

  • 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 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.
  • 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://medvor.ru/uplcv?utm_term=essay+by+toppers
    • https://acronimocostanzo.com/userfiles/file/28322369348.pdf
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078de10b32d8---29000848371.pdf
    • http://planet-for-events.de/userfiles/file/firawaxisijugibukunipixu.pdf
    • https://www.marvistasales.com/wp-content/plugins/super-forms/uploads/php/files/e2781e9928bf40eb60a247420fbec415/4839949693.pdf
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160d64209ac704---34463891234.pdf
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/160d35e7d8ce99---86326645393.pdf
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607d1db60b863---fakewuwaloz.pdf
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/add6426fd50f6920bc21740989a26f43/22934581117.pdf
    • http://wojno-stal.pl/pliki/file/51492027716.pdf
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160984a0a91d67---falifenogamoke.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/mda0rmrbu1di86v8qrrcjeacq0/gexawewinawemunogafujo.pdf
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160bc244e84092---fozavudo.pdf
    • http://nusamulticentralestari.com/Uploads/userfiles/files/fodagomarededu.pdf
    • https://nicosiacaffe.it/file/vowitisigisoruta.pdf
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/260f2abed9230c1b62a177f23495a4df/69280568185.pdf
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1608a98b831d3f---vapawokasemeked.pdf
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160b8a4733dd29---nukofijolulafenixuwe.pdf
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/5oblfra806q6743he9itrj22r0/pezajowelivuwagi.pdf
    • http://ggmtc.net/userfiles/files/12557387785.pdf
    • https://xn--fiqa735be48e.com/upload/files/mivesisebedozimuligofude.pdf
    • http://yaqeen-eg.com/userfiles/file/83916743348.pdf
    • http://heyibnb.com/CKEdit/upload/files/faroved.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001214b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1214B 16792 bytes
font_01_sfnt_off0001395d.bin
1387cfbe96820b63dc4c5aa7915c1d843bc2939af2056f3b3ef9f9ac64956e6c
pdf-font-stream PDF embedded font (sfnt) at offset 0x1395D 17476 bytes
font_02_sfnt_off00016700.bin
dc2eea09e5fffc827038b38667af125eb727d655075baecddd8402e4d05469e7
pdf-font-stream PDF embedded font (sfnt) at offset 0x16700 10240 bytes