Malicious PDF — malware analysis report

Static analysis result for SHA-256 b91c0af708c508db…

MALICIOUS

PDF

85.7 KB Created: 2021-07-02 18:43:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3ec753e7b932ffff50924502ccd2b139 SHA-1: 4004c809d2dd2f844e1b2ed7b7d647056305958e SHA-256: b91c0af708c508db5b48866f667f0d2d6c15d55265611053f8c141993d23fa1d
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, indicating a phishing or malware distribution attempt. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this. No scripts were extracted, but the overall structure suggests it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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 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 http://davidlbrooks.com/clients/868292/File/zufizorubusepidunidapeb.pdf
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/ba7e8c2cd620485432a781fb5ee847cb/97414596142.pdf
    • http://mofrantech.com/userfiles/file/norawozutukexomelija.pdf
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/1607bac4e152cf---84074160785.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/ob0jipsf7kq99dar9d1oc9hb13/79929128906.pdf
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/ul6khqumhs295jhjq3rhtlq06j/ziwejipavava.pdf
    • http://reelproductionshd.com/userfiles/file/manoxefexunel.pdf
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/ff385eec965288d1c9a12dfda77eadc9/65619861766.pdf
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d34598208e2---lafafavikatamafixodapi.pdf
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aaa3dd8dd88---11899378862.pdf
    • http://hiddenforrest.net/clients/76790/File/8710826561.pdf
    • http://techbis.pl/files/file/ritutob.pdf
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607a3ae1dd335---wazudapi.pdf
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/a0a178da60deaa3c3d450c269f87c3ab/xinategelejo.pdf
    • http://deepakbatteries.com/uploads/file/mupuvumunimerudebik.pdf
    • http://driscollandgibson.com/images/edit_images/file/72048684121.pdf
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/qi97vh236plqtbq6eic5bbuqvn/kopabevijorip.pdf
    • http://brightwayconsultancyservices.com/userfiles/file/96226303866.pdf
    • https://avigailpekelman.com/sites/default/files/file/64754335215.pdf
    • http://meteosputnik.ru/userfiles/file/puwoxijenasetudumiju.pdf
    • http://www.findvoters.com/userfiles/file/80953097703.pdf
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160748fc5b1e2d---barewofun.pdf
    • http://colegiosantarosa.com/uploads/imagem/file/67439361465.pdf
    • https://amrapalispot.com/userfiles/file/63430855407.pdf
    • https://www.eziblank.com/wp-content/plugins/super-forms/uploads/php/files/jfk8p3nulqjcj6bqsdmha0r3m2/revadefulisi.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=applied+linear+regression
    • 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_off0000ee02.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE02 16792 bytes
font_01_sfnt_off00010619.bin
2d9479620b0f43179c99ae0b2bd8c40abca03d79287cc8fd2668184b5f050272
pdf-font-stream PDF embedded font (sfnt) at offset 0x10619 10452 bytes
font_02_sfnt_off00011dad.bin
ba224b80a0ed5b9ec9eacfc9e8b4a1b7e2d408016dfa0494a8a8976ccb36b69b
pdf-font-stream PDF embedded font (sfnt) at offset 0x11DAD 16820 bytes