Malicious PDF — malware analysis report

Static analysis result for SHA-256 745156b45885f622…

MALICIOUS

PDF

72.6 KB Created: 2021-09-06 16:17:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e578f73a6249a60454428565824464d2 SHA-1: c634f783246d236aebf7db115b56f27111043233 SHA-256: 745156b45885f6227a6132ab4345adbb1d8e40948f1517e650d00b235e6d5653
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs that form a link farm, with several pointing to compromised CMS upload storage. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links. No scripts were extracted, but the presence of numerous external links indicates an attempt to redirect the user to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://lysgaards.com/ckfinder/userfiles/files/bogakileb.pdf In PDF document text
    • https://damiel.eu/userfiles/file/memamututozevelazomukopa.pdfIn PDF document text
    • http://wittymall.com/multimedia/userfiles/file/89847755552.pdfIn PDF document text
    • http://uro-medical.pl/zdjecia/fotki/file/75282856905.pdfIn PDF document text
    • https://esterkins.de/ckfinder/userfiles/files/mifefebukaxudipa.pdfIn PDF document text
    • http://htygroup.com/upload/files/kazugolipofa.pdfIn PDF document text
    • https://rsun.pro/admin/ckfinder/userfiles/files/56870825324.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a280c704181---66333671365.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/4b050a555298f21095c386ec595aa040/nemevaxa.pdfIn PDF document text
    • http://ediliziaunoaventi.com/userfiles/files/64965951299.pdfIn PDF document text
    • https://yenhuy.vn/upload/files/9007631324.pdfIn PDF document text
    • https://asoriofrio.org/ckfinder/userfiles/files/sakir.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607735699000b---demuzulilafajojolabomiro.pdfIn PDF document text
    • https://unicon-msk.ru/data/files/76917327328.pdfIn PDF document text
    • https://ahreco.com/uploads/news_file/sodonisatizojagujijepezi.pdfIn PDF document text
    • https://jnvhardoi.org/ckfinder/userfiles/files/17929362801.pdfIn PDF document text
    • http://stensoproject.com/userfiles/files/xijitavoberotorinabenepof.pdfIn PDF document text
    • https://vargyasnekonyveles.hu/kepek/other/file/popozika.pdfIn PDF document text
    • https://fsreloading.com/userfiles/files/75262670023.pdfIn PDF document text
    • http://manilag.com/FileData/ckfinder/files/20210627_B72814D25B3CE604.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160afaa0bd636a---bemuzajulimanulaju.pdfIn PDF document text
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/3012889e6662cbc31f0a85c5203b02d3/solewake.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1609c3570ed048---dananotab.pdfIn PDF document text
    • http://prattsofdouds.com/clients/d/d8/d85aab9f4bcbae69c8358f7a9990a0b1/File/muxolatibufodi.pdfIn PDF document text
    • http://dzbnf.com/upload/file///siruj.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160781e968e92d---libina.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=dance+music+manual+downloadPDF 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_off0000b9c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9C3 16984 bytes
SHA-256: 57ad4375f651fd59ee485eba9d292e1bed9259f4dbef0389fb222cfc26a3381d
font_01_sfnt_off0000e511.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE511 10520 bytes
SHA-256: 5664c9d5778e441220bda27a2ce5e8e92bc28c04392df1c2abefb11b99d8557c
font_02_sfnt_off0000fd05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD05 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1