Malicious PDF — malware analysis report

Static analysis result for SHA-256 840c77e5535001b4…

MALICIOUS

PDF

89.6 KB Created: 2021-09-12 01:21:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4efe1ec053b299c2a19c8feeda426403 SHA-1: 217bb3031acc1e68d4f07a604fa313e45600e658 SHA-256: 840c77e5535001b48b73a96563dd3a2408bca73da6faf024608fb341397cb4ef
156 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, and heuristics indicate it functions as a link farm. Multiple URLs point to domains that appear to be compromised or disposable, suggesting an attempt to lure users to malicious sites. The presence of numerous links, some with UTM parameters, reinforces the phishing or malware distribution intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://nhatngudongkinh.com/upload/ckupload/files/binudipewirivaj.pdf In PDF document text
    • https://qkon.ca/images/file/sukeruvasi.pdfIn PDF document text
    • https://estoniapools.com/contents/files/dawen.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613be2739e105---81027883448.pdfIn PDF document text
    • http://oishisushigd.com/uploads/files/12049084251.pdfIn PDF document text
    • https://soalmatematik.com/userfiles/file/disirofowoxuwusunonez.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/a0k3oqohp3omjpoeua5a9bcghg/8194403652.pdfIn PDF document text
    • http://kuryakyn.ru/userfiles/file/zixigenorimotote.pdfIn PDF document text
    • https://knurussian.kr/DATA/upload/files/202109101018245392.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cc194d605a---visinoxipirunes.pdfIn PDF document text
    • https://cooperspick.com/files/gotunepabelezanaxetesadum.pdfIn PDF document text
    • http://nhagiatxanh.com/public/default/ckeditor/files/zewototuwato.pdfIn PDF document text
    • https://cedria.es/DOCUMENTS/FotosFCKEditor/file/rinimofezezuluk.pdfIn PDF document text
    • http://ideviceplus.nl/app/webroot/files/userfiles/files/9400274723.pdfIn PDF document text
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/6f78c115b04b4924849845943f4bdc2a/61090836589.pdfIn PDF document text
    • https://machnhaduong.com/images/uploads/files/46563568822.pdfIn PDF document text
    • http://mavelikaradiocese.org/rapha/ckfinder/userfiles/files/25780484268.pdfIn PDF document text
    • http://balcimimarlik.com/resimler/files/81416197373.pdfIn PDF document text
    • http://vidol.nl/userfiles/file/51559062297.pdfIn PDF document text
    • http://tucholainfo.pl/userfiles/file/rituxumadaxowedawozufu.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea65b15fea---50349314768.pdfIn PDF document text
    • http://www.cda.org.hk/ckfinder/userfiles/files/mukamu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=first+largest+country+in+worldPDF 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_off0000fa32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA32 10824 bytes
SHA-256: 5aba1ea37e182fe0f2592ceae253fbb720a7f266897dfd3e889f2164e5f31772
font_01_sfnt_off00011326.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11326 17696 bytes
SHA-256: 54324417335996a9a1ce311392093b0d7329a8da4a2f8eed5468310050f2c3fb
font_02_sfnt_off000140db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1