Malicious PDF — malware analysis report

Static analysis result for SHA-256 acfc232666812ac1…

MALICIOUS

PDF

91.1 KB Created: 2021-08-13 08:43:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9c57fcc6008c6644a803d78cf024a496 SHA-1: 9cf9ed770ba237ab8eb14ae54fdf645c43147f89 SHA-256: acfc232666812ac1ccb87153c50e1c065175e39ea60ca00cdb838efcd1627c96
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to potentially compromised WordPress sites or disposable hosting. The PDF structure itself does not contain readable content, suggesting its primary purpose is to host these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/df6e31dc5e2cb683feb4f55e32a14382/17126538423.pdf
    • http://ourconn.com/userfiles/file/202107291841225232.pdf
    • http://itineraire-consulting.com/ckfinder/userfiles/files/witugegevorugogojetelepur.pdf
    • http://lussoleathertiles.com/test4/EDITOR/example/v2/userfiles/file/wuwekegaz.pdf
    • https://bitree.com/ckfinder/userfiles/files/welomofotuxilapitarutoluz.pdf
    • http://wahluenfty.com/userfiles/5011409246.pdf
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074030a9fee3---xuzovukenuposopopob.pdf
    • http://xn--49s538bo8ux8c.net/userfiles/file/ladaw.pdf
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b9bfbb6dce4---76100676402.pdf
    • http://dolinakrzeptowa.pl/public/upload/ckfinder//userfiles/files/fumavekem.pdf
    • https://betenenergy.com/sites/default/files/file/81578271468.pdf
    • https://www.bistro-e.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d0cca59ed0---zuwuvijetonafetefato.pdf
    • http://matonaklawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/18146907336.pdf
    • http://aarogyamedico.com/userfiles/file/pepejaloleril.pdf
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/755unjo774c7423l74914algp9/tatuz.pdf
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608ff4fc31d04---sojowu.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/vvp6lelivq43b7lq525d0e30oc/bugewet.pdf
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/hlh5krf3kb5fsfe9nei7ercp41/zanezoxuvajipage.pdf
    • http://libron.pl/fckupload/assets/file/38784192208.pdf
    • https://cargobull.cz/res/file/muxakesigu.pdf
    • http://fzsvybbs.at/userfiles/file/lobebatisusuwut.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=what+are+the+primary+differences+between+monocots+and+dicots
    • 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_off0000fdd9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFDD9 16792 bytes
font_01_sfnt_off000115eb.bin
b4f9e2ef2acc7522593042d3c5032fbde3fb806f7f95622b626cd1a9f2d0c14f
pdf-font-stream PDF embedded font (sfnt) at offset 0x115EB 17712 bytes
font_02_sfnt_off00014463.bin
4c1daa3e76ddeaab739ee4a9698acd2f30b48d4cd4f652fcb1f8b08ae1e122a9
pdf-font-stream PDF embedded font (sfnt) at offset 0x14463 11172 bytes