Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c9d93fa66484af1…

MALICIOUS

PDF

89.2 KB Created: 2021-08-10 14:08:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7c74768ff2269921ca217ffb0cedf30a SHA-1: 17bc08a4d156050fd5c3dd87c72df2991bc3f506 SHA-256: 5c9d93fa66484af1726ab110b07c5f528e66d74dae31ce1816fe0d5039667ba8
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. It contains numerous links pointing to compromised WordPress sites, suggesting it's designed to lead users to malicious content or downloads. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent beyond being a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9904

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://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bdf2749123b---68621148509.pdf In PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607e08c536b1b---fezagidop.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a1a2a080982---78265992209.pdfIn PDF document text
    • https://ensasoft.com.tr/wp-content/plugins/super-forms/uploads/php/files/ojbrfknr8k88ocdovef00tgisr/jedute.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c3477840460---wexepemoxebirowiluse.pdfIn PDF document text
    • https://www.neosynapses.com/wp-content/plugins/super-forms/uploads/php/files/j568pf5kr3b8o4o2sie1ol2mgm/fixiberulixavonuno.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fdfa2b0e1c---64955890467.pdfIn PDF document text
    • https://pmfegypt.com/userfiles/files/nikekuwipugisonadupuk.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160aef357a716b---xudamirojevitu.pdfIn PDF document text
    • http://dbjhockeytournament.com/clients/f/f9/f9ff496842c877cbb4522510b668f2a2/File/tunirigozafijigulilu.pdfIn PDF document text
    • http://tauben-buchmeier.de/kleinberliner-schuetzen/userfiles/files/16551661906.pdfIn PDF document text
    • http://cdwy028.com/uploadfile/file/20210623160027.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/f823fe4293eefead940b8e99310964bf/xuwajabidep.pdfIn PDF document text
    • http://cuatro-pr.org/sites/default/files/file/wegexugezajenolozojefa.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/9d68472489f6fdc125c6627d13289a6d/54097596551.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fb440693c1f---xatetobekopudidonuzuramo.pdfIn PDF document text
    • http://studiogaleazzo.eu/userfiles/files/69732434465.pdfIn PDF document text
    • http://thuephotocopytaihanoi.com/upload/files/xesoziw.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609091f8b09dc---30103169630.pdfIn PDF document text
    • http://laiksmodalux.lt/app/webroot/uploads/userfiles/files/bapigolokuwol.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/rizilanuxodokobod.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/dvau4su3vkqk69hku6p6r4r7r6/lerojexi.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611167e4c1bd7---fevigut.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/a4c0885f58dae06ee4cc7d4e50c4fcdb/nokogur.pdfIn PDF document text
    • http://www.goldenlantern.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9d87a80a7---58883493571.pdfIn PDF document text
    • http://bigband-ulm.de/userfiles/files/25274449353.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=cuantos+votos+son+un+esca%C3%B1o+en+barcelonaPDF 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_off0000f57a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF57A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010d91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D91 10676 bytes
SHA-256: def0b0c7b9e86b0b3f97d07a89cf723f859407b3633c1ef3ac1e0f58580c8c23
font_02_sfnt_off00012603.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12603 18320 bytes
SHA-256: 138df64754df2ca8adb042a2c47b212987155dc63f406bde0c734c3b5cea26cf