Malicious PDF — malware analysis report

Static analysis result for SHA-256 b0855be9ba7249cb…

MALICIOUS

PDF

96.4 KB Created: 2021-09-23 08:37:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d8f984e5464a96e2712dfae704cdc686 SHA-1: e7f329ce700fde54d4ca8ba672fa9eb53951635f SHA-256: b0855be9ba7249cb8de22a32cc7628c7e6a12f1d20ff7dd4c0f8d35b9387f53c
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to domains flagged as link farms or potentially compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO spam. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, offering no direct user-facing content but serving as a vessel for these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9888

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://kayapaliinsaat.net/file/mavasilonurinuvawemunad.pdf In PDF document text
    • http://lamgi.pl/ckfinder/userfiles/files/lolemedosukotafafeki.pdfIn PDF document text
    • https://ntct-dz.com/ckfinder/userfiles/files/35330253213.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613f7797b36f2---zozevawok.pdfIn PDF document text
    • http://www.aceitunasdelguadalhorce.es/ckfinder/userfiles/files/tudagujefotewutekirofijeg.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/rekolezetip.pdfIn PDF document text
    • https://alwillislifecenter.org/ckfinder/userfiles/files/90270347677.pdfIn PDF document text
    • http://emiem.pl/public/upload/ckfinder/userfiles/files/40484546418.pdfIn PDF document text
    • http://jsushibrea.com/uploads/files/85196781362.pdfIn PDF document text
    • https://portecitadelle.portecitadelle.ca/ckfinder/userfiles/files/19561516816.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/67775a570e27268ae3c1caa88c377ec5/wuwifidove.pdfIn PDF document text
    • http://xn--hazrdner-r4a10d.com/alisveris/yollanan_resimler/file/joxisasovezeputozasoneka.pdfIn PDF document text
    • http://holidayservicemarsala.it/userfiles/files/pabazenumixigedubuvomul.pdfIn PDF document text
    • https://0922.sproname.com/files/userfiles/files/99817688834.pdfIn PDF document text
    • http://vitanova-cattery.com/upload/file/11080268549.pdfIn PDF document text
    • http://plkorea77.com/ckupload/files/xaviruk.pdfIn PDF document text
    • http://wpklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/18070647487.pdfIn PDF document text
    • http://nsmpublicschool.org/slbdavbatala/userfiles/file/4703525488.pdfIn PDF document text
    • https://gtijsr.com/userfiles/file/57238010525.pdfIn PDF document text
    • https://exihomes.com/userfiles/files/70392607592.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613efebc0c6ac---zonuwuzakenemapagopo.pdfIn PDF document text
    • https://ssmavidiyar.com/public/content-images/files/xejowuwepidedilimijadeg.pdfIn PDF document text
    • http://jyjjapan.jp/files/ckeditor/files/67472956215.pdfIn PDF document text
    • http://belovosushi.ru/files/59918784125.pdfIn PDF document text
    • http://xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/70213977826.pdfIn PDF document text
    • http://compsult.net/userfiles/file/6404036313.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=boruto+naruto+next+generations+free+onlinePDF 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_off00011696.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11696 10644 bytes
SHA-256: 513652a95922a99affe1fac3bd66301b54b4d987a27ff19b37d647bc13cd030f
font_01_sfnt_off00012f27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F27 17288 bytes
SHA-256: 3939856e17943de40eb6745d4be043118c54754456630356bac4252d3cbb7cef
font_02_sfnt_off00015b8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15B8E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1