Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b096d5cae656a1f…

MALICIOUS

PDF

83.2 KB Created: 2021-09-16 07:11:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: bd63af279241489a3331ea16c0cae7a9 SHA-1: 5be5f3b420802345450055abaa85fba68faa3f79 SHA-256: 5b096d5cae656a1f53efb782c18e197492725cea41de0b8658d829508349f5e0
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to external websites, many of which are hosted on compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a container for these malicious links.

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://bagiez.com/userfiles/file/kunugipisodovenatadotas.pdf In PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131dddebae0b---jilikusawumujupuxa.pdfIn PDF document text
    • http://box8websites.com/ckfinder/userfiles/files/64004738999.pdfIn PDF document text
    • http://uslugi-ogrodnicze.pl/pliki/File/59862065010.pdfIn PDF document text
    • https://ienter.bg/files/bosidoxogekaxipiwilo.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/1613c7ddabfbcc---48790079489.pdfIn PDF document text
    • https://mygrind.ie/userfiles/file/71897735719.pdfIn PDF document text
    • https://shindah.com/images/ckeditor_img/files/nabamivol.pdfIn PDF document text
    • http://e-sheremet.com/img/49415532589.pdfIn PDF document text
    • http://sobateracota.ro/mm/file/14702207346.pdfIn PDF document text
    • http://lenosada.sk/editor_uploads/files/xavarus.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ef79826c58---89604474968.pdfIn PDF document text
    • http://netmode.net/app/webroot/uploads/files/39917834737.pdfIn PDF document text
    • http://marta-galan.com/files/varios/file/wujekazuvekupirunudota.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/6ca3592d672088d71f9ea011c9c9a798/medivajarekedo.pdfIn PDF document text
    • http://camara.acessoainformacao.org/uploads/ckfinder/files/16025974835.pdfIn PDF document text
    • http://www.medicellbank.com/userfiles/files/fiturodawuduv.pdfIn PDF document text
    • https://kme.pl/global/app/webroot/uploads/file/16317214502758.pdfIn PDF document text
    • http://foto-klub.dk/userfiles/file/21059328631.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-9-7/20210907090610110897.pdfIn PDF document text
    • https://ceccarbotosani.ro/userfiles/file/88668210821.pdfIn PDF document text
    • http://gocchame.vn/app/webroot/img/uploads/files/64397374742.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=animal+crossing+n64+english+romPDF 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_off0000d8d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8D9 10804 bytes
SHA-256: 377962f18bcb0534cadc6430161ace8d2ad3de35298f693b23fcea19bceec7c9
font_01_sfnt_off0000f19c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF19C 19644 bytes
SHA-256: a6c651d6148b22bb33a0bf3aa27ac178cece8216bf162addc210abe14abed31f
font_02_sfnt_off0001251d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1251D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1