Malicious PDF — malware analysis report

Static analysis result for SHA-256 dfa858f0d8d6bd77…

MALICIOUS

PDF

81.9 KB Created: 2021-09-20 10:25:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f926c6ae5ae477f4701c973c975954d9 SHA-1: 18ec0b47425a8e6a0a6c983b002ddd2c2d5523d7 SHA-256: dfa858f0d8d6bd7775c4b7bcf0d58fe17f3147016b8601436b69a6f3be3b54e0
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous external URLs, with several hosted on compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The document body is unreadable, but the heuristics and URLs suggest a tactic of luring users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://ucokampen.com/media/files/wiwikevaj.pdf In PDF document text
    • https://szaniterplaza.hu/ckfinder/userfiles/files/tinaxu.pdfIn PDF document text
    • http://topoint.net/userfiles/fckFile/20210904175814.pdfIn PDF document text
    • https://losaltos.com/wysiwygfiles/file/94434682242.pdfIn PDF document text
    • http://zerosquareonline.com/file/95291999696.pdfIn PDF document text
    • https://baust.edu.bd/app/webroot/ckfinder/userfiles/files/17475431981.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1614136d6e5c1c---polugokuxiwumokajozexis.pdfIn PDF document text
    • https://wroclaw-effatha.pl/grafiki/file/52340877029.pdfIn PDF document text
    • http://coverybox.box8websites.com/ckfinder/userfiles/files/42637224147.pdfIn PDF document text
    • http://ecme.site/2015/vat/upload/files/tipategitobesodimademapol.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/mugixuko.pdfIn PDF document text
    • https://evrenmentese.com/upload/ckfinder/files/bobofabovirilororisubeb.pdfIn PDF document text
    • https://taevlingar.se/images/pages/file/33298545950.pdfIn PDF document text
    • https://clinicamanila.com/ckfinder/userfiles/files/24200457565.pdfIn PDF document text
    • http://hangquangauto.com/files/33113342003.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1613e4ca6194b5---fekedevizenasakok.pdfIn PDF document text
    • http://winkeleninzundert.nl/uploadimages/files/69619921589.pdfIn PDF document text
    • http://www.gieskestukadoors.nl/ckfinder/files/files/lolajikuzuxe.pdfIn PDF document text
    • http://tribo.kz/userfiles/File/wanedizodasowozapawudosu.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/7368040755e851ab7016408c8e79a421/75566279768.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/16135f18f7df01---gozegezixu.pdfIn PDF document text
    • http://hrjok.com/uploadfile/file/mofovogid.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=restaurant+story+mod+apk+unlimited+gemsPDF 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_off0000dbf3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBF3 17096 bytes
SHA-256: 4bf67beab9f4819d2d00846da1f937f8e14d98a0f298749f1fd3be0283f52f19
font_01_sfnt_off000107e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011ffb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FFB 11084 bytes
SHA-256: b97cff543f6d1afcc23f5f4721db7ff35086f7a4ebfbe3b838dd4e4334bfca44