Malicious PDF — malware analysis report

Static analysis result for SHA-256 c350333b00cb8180…

MALICIOUS

PDF

77.6 KB Created: 2021-09-25 20:28:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ff104b5b35d5d8aa515f45db4ffd98b9 SHA-1: e8f934bd346de9b1600b9d373937b079281f8d99 SHA-256: c350333b00cb8180bff731e35873facc0e67502b48b7b16850aacbbf32e06596
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or are part of a link farm hosted on disposable domains. ClamAV and ML classifiers also flagged this PDF as malicious, specifically identifying it as a phishing trojan. The primary function appears to be redirecting users to external sites, likely for malicious purposes such as phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9804

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 http://gruaszarate.com/ckfinder/userfiles/files/tamodabefemeteravavula.pdf In PDF document text
    • http://www.kowel.com/ckfinder/userfiles/files/1631592701.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/16132874930c2b---vumirumu.pdfIn PDF document text
    • http://yunnanyingxiang.com/ckfinder/userfiles/files/kujijadunukofenekive.pdfIn PDF document text
    • http://czyxchem.com/upload/files/67904138053.pdfIn PDF document text
    • http://kirakuramenandsushi.com/uploads/files/zetag.pdfIn PDF document text
    • http://barrybusiness-crm.com/ressource/devis-photo/files/mitigakowupodebuzu.pdfIn PDF document text
    • http://precisao.org/files/files/gaxolazorunasep.pdfIn PDF document text
    • https://sunwayhk.com/louis/STARKGROUP/ckfinder/userfiles/files/kokeguvaraxom.pdfIn PDF document text
    • http://tunglamgarden.com/images/fck/file/5155729229.pdfIn PDF document text
    • https://samirkumarpaul.com/ckfinder/userfiles/files/noxupakenek.pdfIn PDF document text
    • https://larustt.com/upload/ckfinder/files/22450860198.pdfIn PDF document text
    • http://laibros.com/ckeditor/userfiles/files/58826281434.pdfIn PDF document text
    • https://greenfuturevietnam.com/Upload/files/70259609524.pdfIn PDF document text
    • https://karthikaspices.com/uploads/file/kupugenomuzofa.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161493dc174de6---vexidikowomibunu.pdfIn PDF document text
    • http://zatuchlina.cz/upload/file/9198456279.pdfIn PDF document text
    • https://www.idd.no/ckfinder/userfiles/files/zimovozusugenopugumunewek.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1613436ad05f1e---74445349284.pdfIn PDF document text
    • https://doina.md/fckeditorfiles/file/46931935003.pdfIn PDF document text
    • http://teleinwestor.pl/userfiles/file/16835409309.pdfIn PDF document text
    • http://ykzn8.com/upfiles/editor/files/58086673610.pdfIn PDF document text
    • https://granitabrasive.ro/editor_up/9461607941.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/bcdcb39edffcea6fa9b004894f1c1524/32279796904.pdfIn PDF document text
    • http://3e3i.com/UserFiles/file///80380511431.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/94f5de32ae84d2b68f6de0c63095ad96/levupokid.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=confessions+of+an+advertising+man+pdfPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b832.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB832 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d044.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD044 15976 bytes
SHA-256: 4bf1fe0e2c013c079edbf2651de2751647cf0e4801ee2012efef5e1f25a00ae2
font_02_sfnt_off0000f8b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8B3 16232 bytes
SHA-256: 01cd0e4798e93fb086042d610f43ddeed7bf091af48aa863f5c4a4f61b651684
font_03_sfnt_off00010e8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E8D 10892 bytes
SHA-256: 5e82424588372555e29c4e2267a394d2dfb6be54b937bace313c883e880e3dd0