Malicious PDF — malware analysis report

Static analysis result for SHA-256 efc4db2cde66215a…

MALICIOUS

PDF

79.5 KB Created: 2021-09-13 12:36:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 9d757c64124971bbcd7d14d4a755c56b SHA-1: bf82a4680e2329937ce98cb1c6a8c95013d1bb57 SHA-256: efc4db2cde66215a88ae926923f2f0b5cd181a79b8d9ca033d21574da3104b3c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to various domains, some of which are hosted on compromised WordPress sites. The presence of multiple external URIs and link farm heuristics indicates an attempt to redirect users to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://hongsung114.com/files/fckeditor/file/tamulekotemudalitezu.pdf In PDF document text
    • https://fptica.ru/images/file/detesiri.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16130429a7e532---9651227686.pdfIn PDF document text
    • http://tech-sub.com/userfiles/file/93476050374.pdfIn PDF document text
    • https://comfort8889.com/upload/files/koripevux.pdfIn PDF document text
    • https://shirbandifelt.com/userfiles/file/24032531490.pdfIn PDF document text
    • https://betenenergy.com/sites/default/files/file/53941560548.pdfIn PDF document text
    • http://japanbizkorea.com/userData/ebizro_board/file/kajurizafoxuwinafutiv.pdfIn PDF document text
    • https://vidaleve.net/ckfinder/userfiles/files/gazon.pdfIn PDF document text
    • http://museodegliarazzimarsala.com/userfiles/files/jesosejim.pdfIn PDF document text
    • http://kedehg.com/ckfinder/userfiles/files/47465933410.pdfIn PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/mivogiduritadakonone.pdfIn PDF document text
    • https://shih-tzu.ro/files/file/14772202173.pdfIn PDF document text
    • http://aitrans.org/UploadFile/file/F1202109111753567659.pdfIn PDF document text
    • http://antropolog.ru/userfiles/file/difotonamal.pdfIn PDF document text
    • https://sanipro.ma/app/webroot/uploaderfiles/2841707772.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f155ba9533---5683519289.pdfIn PDF document text
    • http://www.taxivanclass.com/uploads/ckfinder/files/96738896218.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/563ef8f482176558c92a7fb139925943/80205315062.pdfIn PDF document text
    • https://sportuna.be/ckfinder/userfiles/files/jufir.pdfIn PDF document text
    • http://aci-immobilier-douai.fr/userfiles/files/23497168952.pdfIn PDF document text
    • http://weorderfood.com/uploads/files/fibodaxixi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=hard+words+that+start+with+rPDF 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_off0000d68d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD68D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE9F 16992 bytes
SHA-256: 008d4095e5e2b06fcaed455eae200cb7ce3062a2ff7d4f03b0ad2985c0c79299
font_02_sfnt_off00011a4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A4B 10140 bytes
SHA-256: 2c3f0edd7433a15a94e92525b43c9ca55bd0c6b0f0eac66ad1717c8e8f29d59a