Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c1c7d1385f8c1c6…

MALICIOUS

PDF

81.9 KB Created: 2021-09-02 13:25:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: f83441855cdd9b8fac905e8056919130 SHA-1: 61f7f29c390974cd35d6512d14f5029ef605d4ba SHA-256: 3c1c7d1385f8c1c66e36753d4b7ac280a9d9f0fc791d852231aa10de82b9d994
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed for redirection. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and URL patterns suggest an attempt to lure users to external sites, likely for further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://anm-av.de/uploads/files/sazuzefefusij.pdf In PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a5ef6e9c704---fenidafobinunu.pdfIn PDF document text
    • https://tpijobportal.com/ckeditor/ckfinder/userfiles/files/sovibojuwab.pdfIn PDF document text
    • http://cobansut.com/userfiles/file/zarawezarirazid.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8420c61ab5---vaxujiwopixemomixifu.pdfIn PDF document text
    • http://fiumevivo.it/userfiles/files/36174406594.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609adce08c115---73045054290.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160779e8b14a94---ditazotarunodi.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c57ba2e08dc---mefubivibosaxuxapoku.pdfIn PDF document text
    • https://webupdate.ca/wp-content/plugins/super-forms/uploads/php/files/mr2o6uc8sffdi09s3165ucm5q6/71351983024.pdfIn PDF document text
    • http://spiregene.com/image/files/20210813_013324.pdfIn PDF document text
    • http://astro2sphere.com/admin/images/file/35737872064.pdfIn PDF document text
    • http://mistral-paints.cz/userfiles/files/ponalus.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/810e1dcb4c0b47ea850307212e01b2bf/leberagaxanijabidid.pdfIn PDF document text
    • http://suacuacuonthanhhoa.com/upload/files/guzabu.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/3665c59e7ceedbddb71a7413d7ce2c7a/41337237812.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/f6c64a4d898fd0ceeacee342517179cb/62150134994.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607db84d98668---26370723290.pdfIn PDF document text
    • https://bahceneryaman.net/public/content-images/files/92113423887.pdfIn PDF document text
    • http://jiehuist.com/userfiles/files/10324260846.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/6b875a97f9308c70a2182123ea8b065f/22612668839.pdfIn PDF document text
    • https://atl-50.com/files/file/kebimirov.pdfIn PDF document text
    • https://birsamundapark.in/userfiles/files/tesofukolozini.pdfIn PDF document text
    • http://abbeytraining.net/userfiles/file/43516057940.pdfIn PDF document text
    • http://www.eau-msu.ru/ckfinder/userfiles/files/77253320065.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=schaum%27s+outline+of+discrete+mathematics+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_off0000db27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB27 17252 bytes
SHA-256: 780e5e5a82aefaeb377ad7d486a106380db1e79f722c799f6e4066d11b805c1a
font_01_sfnt_off000107b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107B2 11096 bytes
SHA-256: 09d6f97ad187b461c8c6be7c121551693010990b2fc7605509c911634c4722c9
font_02_sfnt_off00012162.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12162 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1