Malicious PDF — malware analysis report

Static analysis result for SHA-256 635a055b247caebc…

MALICIOUS

PDF

75.6 KB Created: 2021-09-09 08:08:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: bdc163ac1cd50d01e79cafc807916c7e SHA-1: f9dd995bfd6742b868caa1b21571f42205177adf SHA-256: 635a055b247caebcb9e2fb9b2ad59d8ce4bbdbeadef0e9b341f6898adcfc9d9e
164 Risk Score

Malware Insights

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

The file is a PDF containing embedded JavaScript, which is a common vector for malicious activity. Heuristics indicate it's part of a link farm, directing users to compromised WordPress upload storage and other disposable hosting sites. The embedded JavaScript likely attempts to exploit vulnerabilities or redirect the user to phishing or malware download sites, as suggested by the ClamAV detection and ML classifier.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://infrive.ru/uplcv?utm_term=pdf+to+csv+converter+online PDF link annotation
    • http://3bbb.fr/ckeditor/upload/files/38236855060.pdfIn PDF document text
    • http://enovosti.info/ckfinder/userfiles/files/dolobifexoti.pdfIn PDF document text
    • http://aaz.sk/editor_uploads/files/37445566871.pdfIn PDF document text
    • https://szabolcsipeter.com/userfiles/file/pejivuresodixidu.pdfIn PDF document text
    • http://perechen-jurnalov.ru/js/ckfinder/userfiles/files/tapejipimoridifenabowet.pdfIn PDF document text
    • http://vdavloeren.be/userfiles/files/dukutenowurolelajum.pdfIn PDF document text
    • http://www.jacenter.org/js/ckfinder/userfiles/files/67494049374.pdfIn PDF document text
    • https://xn--22ck6bdp5cach0mc23a.com/ckfinder/userfiles/files/kanajitukepatuler.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/161342975c5b8c---85430271007.pdfIn PDF document text
    • https://tonwen.org/userfiles/file/28838714702.pdfIn PDF document text
    • http://suamayin.biz/userfiles/file/fepisowe.pdfIn PDF document text
    • http://www.benyowsky.com/resources/files/50818369336.pdfIn PDF document text
    • https://landtop.com/filespath/files/20210905121045.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613477dc788f3---66730854941.pdfIn PDF document text
    • http://www.cddfct.com/up_files/file/wikuzobofexuloda.pdfIn PDF document text
    • https://profix.fr/ckfinder/userfiles/files/pelekedix.pdfIn PDF document text
    • http://ulleungroadtour.com/FileData/ckfinder/files/20210907_0C5D1F98413F774C.pdfIn PDF document text
    • http://reclameindex.nl/images/uploads/61756800819.pdfIn PDF document text
    • https://biomisszio.hu/tmp/29750379471.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1612ef28c75630---wuseburanobuke.pdfIn PDF document text
    • https://tepatsasaran.com/contents/files/wuzoleniwodinejewazo.pdfIn PDF document text
    • http://plafondchauffant.fr/img/user/file/40968071156.pdfIn PDF document text
    • https://www.bevillelecomte.ovh/ckfinder/userfiles/files/60429440578.pdfIn PDF document text
    • http://hosungtour.com/FileData/ckfinder/files/20210908_B8C630383A502DE6.pdfIn PDF document text
    • https://herfection.herfection.tw/upload/ckfinder_temp/files/20210904015029.pdfIn PDF document text
    • 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_off0000c5f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000de08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE08 10372 bytes
SHA-256: 99672cbfd838269197559f55c1806efde1ebad1128dc5bfd05903b8a463ad6e5
font_02_sfnt_off0000f598.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF598 16832 bytes
SHA-256: 4cc8c5fc7e52e5fa768ea88cae4e687a40f280edd0790f7165a6ed2968bd5e98

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