Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8939b0754bca068…

MALICIOUS

PDF

83.7 KB Created: 2021-08-26 06:02:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bee82d46ea477540ca1be3ea949fd8a9 SHA-1: 45002e869eb4730fbe6ac2544b2b7cdb98636cde SHA-256: c8939b0754bca068d3e2c634c883bff2f750db02ecbca7afd7268dc1e6bc035d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF sample was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. It contains numerous embedded URLs pointing to compromised WordPress sites and other domains, suggesting it functions as a link farm for phishing or malware distribution. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://medvor.ru/uplcv?utm_term=focus+groups+with+children
    • https://chamsocmuihong.com/wp-content/plugins/super-forms/uploads/php/files/nbh3rcj13ls95olhb670k5skr3/37826457607.pdf
    • http://montpellier-business-plan.fr/mbp/upload/images/images/upload/ckfinder/lemokanakenisunusuzofuxe.pdf
    • http://eviljoy.com/UserFiles/File/66454698833.pdf
    • http://miwon.com.vn/app/webroot/uploads/files/63307084934.pdf
    • http://misterholidaysanprisco.it/userfiles/files/24001385051.pdf
    • https://ce-mi.pl/uploads/userfiles/files/79576683239.pdf
    • http://chhsclassof70.com/clients/1/1f/1f6d1b94cf555b90b9f410dfa82aea5f/File/jipamaxifukiwibewetu.pdf
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/1607b90dd92de2---sibujefetuden.pdf
    • http://starlightcelebre.org/clients/4/43/43e9139217482d7666ce300faf566241/File/kifejose.pdf
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160884910bcfda---88913905636.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a9fa860cf39---84976626084.pdf
    • http://brandnewgoods.net/userfiles/file/paxorolazetepilolawomu.pdf
    • http://paliukenas.lt/i/File/43255537781.pdf
    • http://patrick-vallot.com/upload/files/91080657009.pdf
    • https://girisimhaber.com/uploads/file/pozukemaxorifo.pdf
    • https://bloomeng.com/uploads/79862210442.pdf
    • https://devcons.org/uploads/userfiles/files/zapakejegapasavudilivi.pdf
    • https://jiu-hang.com/upfiles/editor/files/21188712042.pdf
    • http://belgium-ex.com/images/blog//file/94872679418.pdf
    • http://abnicum.com/files/file/63320084821.pdf
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/23e568c97c395e59534b174be5ed4d31/85064307202.pdf
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/e5997a495f64c21ffc75ea1ac9da6522/vajogaxuvukaziruxevi.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_off0000e383.bin
b3c0597555ae8a8dea96bcab68348c70055fc6cc0eae1ff4694fe0fa4efcb923
pdf-font-stream PDF embedded font (sfnt) at offset 0xE383 16752 bytes
font_01_sfnt_off00010e9f.bin
4eb18f8932b4397c7e08949b4cc17687d386bd91a61bd14fc0deaba35af2716e
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E9F 10796 bytes
font_02_sfnt_off00012743.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12743 16792 bytes