Malicious PDF — malware analysis report

Static analysis result for SHA-256 83c234b84885142a…

MALICIOUS

PDF

68.1 KB Created: 2021-09-17 12:51:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2dee0b24827b920572a7b9e2c4b76ca8 SHA-1: d7dbcba346badbc14b82709928bff72f4604a6d9 SHA-256: 83c234b84885142a20c0a871792b53850c71a13063fb40e73124171888183690
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with several heuristics indicating it functions as a link farm. Notably, some links point to compromised WordPress upload directories, suggesting a potential distribution point for malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://panziofabian.hu/fck_kepek/vuwikageleferixotemeg.pdf In PDF document text
    • http://tko.wavedev.net/img/files/files/68393970028.pdfIn PDF document text
    • http://taiwan-casters.com/userfiles/file/84915323108.pdfIn PDF document text
    • http://swancentive.com/cote_dor_import/admin/ckfinder/userfiles/files/zofesixuvexuvexovezapugi.pdfIn PDF document text
    • http://gorsilawfirm.com/userfiles/file/watuzaku.pdfIn PDF document text
    • http://harryreichert.de/uploaded_pics/News/file/55965682462.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/072e10c1508e7e01492b97a13f298780/lokomuduf.pdfIn PDF document text
    • http://stoewebdesign.no/userfiles/file/13291754362.pdfIn PDF document text
    • http://jyjwqj.com/uploadfile/file///2021091706005698.pdfIn PDF document text
    • https://vico-domrep.com/ckfinder/userfiles/files/firoladokozidasem.pdfIn PDF document text
    • https://www.hkha.com.hk/ckfinder/userfiles/files/gagofox.pdfIn PDF document text
    • http://av72-reklama.ru/userfiles/file/163051538342d0f7ee600116ffc6b2.pdfIn PDF document text
    • http://klhl.com/userfiles/file/pagiporibowuzidi.pdfIn PDF document text
    • https://bda.ch/ckfinder/userfiles/files/sijosomame.pdfIn PDF document text
    • https://rajatotogroup4.com/contents/files/lakajajewudavoga.pdfIn PDF document text
    • http://kagoshimakojintaxi.com/userfiles/file/keviwexawawonug.pdfIn PDF document text
    • http://wwsm-us.com/files/file/96779327745.pdfIn PDF document text
    • http://preciz.com/uploads/wysiwyg/files/ruxaxo.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1613d337a32108---40203711634.pdfIn PDF document text
    • http://reclameindex.nl/images/uploads/kepoxen.pdfIn PDF document text
    • https://paroles-vives.com/ckfinder/userfiles/files/lezujoseki.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c56535694e---wukazupudogivuw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=download+3d+scanner+pro+apkPDF 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_off0000ad15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD15 14832 bytes
SHA-256: 7d4240144280d6cc780013983cf6ece431c0a8114d99e5443f73d914fa8b7555
font_01_sfnt_off0000d2a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2A5 10668 bytes
SHA-256: f9183709f61b2d15679830ee4815c8173b812347f6305629aae4b41269eefdd2
font_02_sfnt_off0000eb58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB58 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1