Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc4e67cf99378d2b…

MALICIOUS

PDF

81.2 KB Created: 2021-09-20 16:19:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f8c63ab10fdfec835992b57ee633deb9 SHA-1: 5ab3178849b7379d9c26952ec09ba334c5675afe SHA-256: bc4e67cf99378d2b4a639919f863fccf73085ecc6b1fe95727cc75b0d001f219
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to obscure the ultimate destination. While no scripts were explicitly extracted, the PDF structure and heuristic firings indicate a likely attempt to lure users to malicious sites.

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 http://huyminhplastic.com/upload/files/lodolipefu.pdf
    • http://arcadia-fitness.es/userfiles/file/zujewovuvidob.pdf
    • http://motovelo-nmsk.ru/userfiles/file/juxakokoguwidonutoniti.pdf
    • http://brilsports.ro/userfiles/file///21707181863.pdf
    • http://ngnjl.com/userfiles/files/96499808475.pdf
    • http://qhzs88.com/admin/fckeditor_upfiles/file/2021091403322980554.pdf
    • http://www.weilandensemble.nl/ckfinder/userfiles/files/98310956619.pdf
    • https://floridainvestment.cz/files/file/kuxowabejitivaxu.pdf
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/16140bae672011---biputuzaruk.pdf
    • http://dennehylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/negekesedeluburekonuzef.pdf
    • http://rts-3.ru/upload/files/numerivolunogeta.pdf
    • http://inspeq.eu/public/files/98150964922.pdf
    • http://kondicionery-dolgoprudny.ru/upload_picture/file/41993038645.pdf
    • http://hiro-seiko.com/upload/files/zusorepigereboxinewo.pdf
    • http://nt-module.ru/ckfinder/userfiles/files/megepepiviludim.pdf
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/27d810971254b0ea285e3bc278ba1ee1/lagewo.pdf
    • http://razzledazzleevents.in/userfiles/file/bubekisajisobosop.pdf
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/8c1fa9df7034517eeffadbdd4c0571cf/69902296758.pdf
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/1716f822b5b8e5c8554a2ccdfbf6aacd/58820563524.pdf
    • http://slkuang.com/v15/Upload/file/20219202048142603.pdf
    • http://www.sec-ollivier-associes.fr/www/upload/file/tinopepigujobozofep.pdf
    • https://sibois.eu/userfiles/file/fadilesofoxuri.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=d%26d+5e+oriental+adventures+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_off0000d121.bin
3697e6456a71496a84d1dcf6228ced7fc37106cd4680c79a50f4d75ea9ccba05
pdf-font-stream PDF embedded font (sfnt) at offset 0xD121 21916 bytes
font_01_sfnt_off00010b55.bin
f695977626623e59fedb2fbedebd468d0acf89ff6f6ceafeb3cee4351ddee6c8
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B55 9076 bytes
font_02_sfnt_off00011dfa.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11DFA 16792 bytes