Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c214042d31f217c…

MALICIOUS

PDF

84.1 KB Created: 2021-09-06 14:49:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c647e2b916b1d7c6d893d542bc72d4ee SHA-1: 1fbdae3466c47c270f4996073f06f475febe5a9e SHA-256: 0c214042d31f217c88c7f74f4e9c56a289213e131b28d5ddf760eab0eec1e0a0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting it's used to distribute malicious content or phishing lures. The document body is heavily obfuscated and contains metadata from wkhtmltopdf, but the primary threat appears to be the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://detmers-kontejner.hr/files/xiposimivunulesamesuzuba.pdf In PDF document text
    • http://vivaibonomo.it/userfiles/files/wuseporezewokiwaped.pdfIn PDF document text
    • https://aduanaldelvalle.com/userfiles/file/resuzufasufididedutetep.pdfIn PDF document text
    • http://lukoilmarine.com/ckfinder/userfiles/files/66745245338.pdfIn PDF document text
    • http://yuhenganquan.com/userfiles/file/20210822104406_1330750520.pdfIn PDF document text
    • http://signauction.net/userfiles/file/99184724381.pdfIn PDF document text
    • http://e3edu.vn/public/ckfinder/core/connector/php/connector.phppublic/uploadsfiles/8902610200.pdfIn PDF document text
    • https://camping-du-lac-dijon.com/fichiers/zobekeviruvujojixafo.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/32957417654.pdfIn PDF document text
    • https://tonitomov.com/picture/file/20002239264.pdfIn PDF document text
    • http://didula.com/img/file/voferijezatadinemajonu.pdfIn PDF document text
    • https://abandassociates.com/ckfinder/userfiles/files/53246311196.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089e21f5b2b3---jijaxedafedepop.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609c41be29bd0---funado.pdfIn PDF document text
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/932347b3a747a26b6d20341aeecb1f08/sonavatatuwebodelunilez.pdfIn PDF document text
    • https://qian-ho.com/upfiles/editor/files/ritelupif.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/cc164caab278e2a025ca0e73c04faac2/85993367735.pdfIn PDF document text
    • https://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/e0f22a98d1c2585bdaf2297e3345255b/68204983274.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/1611e67527e040---55716464771.pdfIn PDF document text
    • http://fine-cottage.ru/userfiles/file/fosipevutu.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ab889d68ddf---tirijipumezunusujeju.pdfIn PDF document text
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076c46507fa6---81576252326.pdfIn PDF document text
    • http://kubabus.cz/novy-web/upload/file/vemowefitiv.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d4316d17352---6884975062.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/160a19de61f048---bifewosalire.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=insuficiencia+mitral+ecocardiograma+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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e64b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE64B 16632 bytes
SHA-256: 068c73bf40fbc886285d9c8826ab5a97eaab1c5d2811c030a6807be8e4d9cf3a
font_01_sfnt_off00011149.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11149 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012960.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12960 11012 bytes
SHA-256: 1397bac02db7bcd1375d30f91c6ebc6abfb6153de8e9ba07d33f83f2fe163855