Malicious PDF — malware analysis report

Static analysis result for SHA-256 855c6ea12b755210…

MALICIOUS

PDF

79.2 KB Created: 2021-07-07 06:44:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 0482e39ebaff15ddc6d22fef05f663d0 SHA-1: c1edd177ab81be1f3ca5592864caf0ad6393aed8 SHA-256: 855c6ea12b7552107fc078c45a700e2967931ea6ba57e8c25ee9005dfc18bf89
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and link farms, many hosted on compromised WordPress sites, suggesting an attempt to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to host malicious content or redirect to phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9927

Heuristics 6

  • 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 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://huntic.ru/uplcv?utm_term=microeconomics+a+contemporary+introduction+pdf PDF link annotation
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/jt5tttulg820bf5u8culpgpjgq/juvexetidat.pdfIn PDF document text
    • http://dioceseofniranam.org/userfiles/file/5300899386.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160adef8a14c5b---2251540922.pdfIn PDF document text
    • http://hibertek.com/image/files/20210629_071448.pdfIn PDF document text
    • https://cls-toronto.com/wp-content/plugins/super-forms/uploads/php/files/d93255e96fde6e1d76bdc6abc6c9b1c0/73320244780.pdfIn PDF document text
    • http://goteneplast.se/files/images/file/muzogozewipob.pdfIn PDF document text
    • http://botanicgardenscafe.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160862220a2d29---fuvasimirekedipelebis.pdfIn PDF document text
    • http://abwcoliseum.com/uploads/files/jodevululugemituxa.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/160c8bd204ebfa---vazezew.pdfIn PDF document text
    • https://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/jv4vo0ajhm1ro26mjvrp31u18k/21056880682.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e1f2d5346c---51727056306.pdfIn PDF document text
    • http://thevelascofamily.com/clients/11614/File/rimilukepesabukuli.pdfIn PDF document text
    • https://medgarlci.com/wp-content/plugins/super-forms/uploads/php/files/9565b715d1fb42f688fb066b966e6527/makoxewagusawepaposa.pdfIn PDF document text
    • http://jsushibrea.com/uploads/files/25588572915.pdfIn PDF document text
    • http://sbs-group.co/userfiles/files/33316899535.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/0a68ad827864a25da902e664b8f7fb14/47029765219.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160998b2ce50a5---pagakuwuwibabujelovijaxa.pdfIn PDF document text
    • http://kadh.kr/bobod/upload/file/nabilupasovamero.pdfIn PDF document text
    • http://saptpadi.com/files/file/26733564907.pdfIn PDF document text
    • http://funkyspa.net/ckfinder/userfiles/files/xoril.pdfIn PDF document text
    • http://ih-consultant.com/ckfinder/userfiles/files/migotalofusosudajojojire.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608203ff4871f---88903650051.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16094fffb173fc---gelesosibamunitekivu.pdfIn PDF document text
    • http://architects-desk.com/uploadsfile/87830781303.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/f805807b13ccb55d72bfc41d8c80ae71/gutena.pdfIn PDF document text
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000be10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE10 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d627.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD627 10944 bytes
SHA-256: 7df14314f0c84a77511cf6d47894f30ce8ce57f42b5b179617336a0a4be750a6
font_02_sfnt_off0000ef8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF8F 16084 bytes
SHA-256: a79c9caf7d9fe7d7e6557dd08284a48a0650ee9668136fadcfdab94fba17ddb2
font_03_sfnt_off000104bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104BF 16568 bytes
SHA-256: 1d9dd93b2684c74aff64b511894664464467b2cea352f07eb6e58941dacbe24b