Malicious PDF — malware analysis report

Static analysis result for SHA-256 4159c69cb6f04bc2…

MALICIOUS

PDF

75.5 KB Created: 2021-09-17 05:15:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b035f34736b26a80cbddefbdad09f12d SHA-1: 7dc6e64f312b602d23b6161117eed755113bd9bb SHA-256: 4159c69cb6f04bc25037c7da5ebd64e10b99331f458ee7b3926adf53802e0214
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample is a PDF file containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting an attempt to distribute malicious files or redirect users to phishing sites. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 http://spbmedaks.ru/sites/default/files/uploads/13428923283.pdf In PDF document text
    • https://webbsoil.com/home/webb/public_html/ckfinder/userfiles/files/liroronefibijuwaduzogal.pdfIn PDF document text
    • http://www.stsmcc.org/www/js/ckfinder/userfiles/files/fisunulexizepegol.pdfIn PDF document text
    • http://quangcongluc.com/upload/files/62186290190.pdfIn PDF document text
    • http://aeusjtu.pretty-match.com/upload/files/97713804620.pdfIn PDF document text
    • http://densayhongngoai.com/uploads/userfiles/file/97240776406.pdfIn PDF document text
    • http://carzip.biz/files/uploads/files/lugopibe.pdfIn PDF document text
    • https://alarouba.com/ckfinder/userfiles/files/gunapejinowifojanot.pdfIn PDF document text
    • http://studiotecnicopinto.it/userfiles/files/6971019474.pdfIn PDF document text
    • https://bhiringisamsankalimandir.org/userfiles/file/dobotosizew.pdfIn PDF document text
    • https://samsungdvm.net/upload/ckfinder/files/kiwazizuzipunizafusobubev.pdfIn PDF document text
    • http://life-worldwide.org/assets/uploads/files/17940232141.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139f7038576b---wenifowawunetoliza.pdfIn PDF document text
    • http://execdentalclinic.com/uploads/ckfinder/userfiles/files/vidifomipigagawavojojif.pdfIn PDF document text
    • http://littlepearlspublishing.in/data/eimages/file/34230871136.pdfIn PDF document text
    • https://gbagencement.fr/uploads/file/62619066635.pdfIn PDF document text
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/def0d082b98ffeaafeadc06cd4e0073a/43312783100.pdfIn PDF document text
    • http://zsdbiopharm.com/upload/files/12968989720.pdfIn PDF document text
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/f48b9ebbbdfee9ad7cc59d6d2b71538b/42277981741.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/a01edff02ca7993536a1caadef4be192/67507782752.pdfIn PDF document text
    • https://swalaya.in/userfiles/file/gifabojotup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=game+horror+ppssppPDF 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_off0000c5b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5B8 17036 bytes
SHA-256: 5948f07c838a76d1ff2647d64a0cba9250897c612c56ad5f210254b13e86b875
font_01_sfnt_off0000f1d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1D5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000109ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109EC 10216 bytes
SHA-256: 69b9e1b3acf644456be40f6ea3609eae5b4c97cfc91457faf1a6545605091abd