Malicious PDF — malware analysis report

Static analysis result for SHA-256 759a37fd1e12a3dd…

MALICIOUS

PDF

73.3 KB Created: 2021-09-11 12:31:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 43d831d8e9eef31d73846f081121589d SHA-1: d794645879bbd1c094cb873d6fccbac11d3d041c SHA-256: 759a37fd1e12a3ddec3b3223d60e5ea391cd197a133e56fd33f75586332e1fcc
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised or disposable hosting, suggesting an attempt to redirect users to phishing sites or download further malware. The presence of multiple links on disposable hosting and compromised CMS upload storage reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • 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.
  • 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://peaceinsrilanka.lk/ckfinder/userfiles/files/putavojosibava.pdf In PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/203a76fe55238d7a6b1a148a66851191/maver.pdfIn PDF document text
    • https://www.pactforfamilies.org/ckfinder/userfiles/files/81316289102.pdfIn PDF document text
    • https://olivier-daulte.com/ckfinder/userfiles/files/91759634392.pdfIn PDF document text
    • http://thaifilmind.com/UserFiles/file/rebetazorasop.pdfIn PDF document text
    • http://speakingaboutnetworking.com/ckfinder/userfiles/files/seguvadurirapozuluxepetet.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/f7965769f2df49c6212b7e50dc67f35d/23888555152.pdfIn PDF document text
    • https://psychotherapie-coeppicus.ch/upload/file/7367962730.pdfIn PDF document text
    • http://dobrejaja.com/Upload/file/535110949.pdfIn PDF document text
    • http://casadiriposomarsala.it/userfiles/files/muwomudolijojekidapu.pdfIn PDF document text
    • http://toeicspeaking.net/_UploadFile/Images/file/66421781028.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131a286d222d---56416838028.pdfIn PDF document text
    • https://siltri.com/fck_upload/file/82580589076.pdfIn PDF document text
    • https://irish-setter-zucht.info/ckfinder/userfiles/files/93654507102.pdfIn PDF document text
    • https://www.auto-ecole-acm.com/ckfinder/userfiles/files/49990032192.pdfIn PDF document text
    • https://www.verimevzabavu.cz/ckfinder/userfiles/files/sofotetebapupija.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/nizuredu.pdfIn PDF document text
    • https://cuatudongsaigon.net/uploads/files/lafosubimabanapagibulusiz.pdfIn PDF document text
    • http://tzsunup.com/upload/77802699348.pdfIn PDF document text
    • http://pietrek.com/MARCUS/files/file/soxofetidavegelonad.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161380ba406624---34455463600.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161358e835f925---23293373633.pdfIn PDF document text
    • http://ttc-investco.com/img/files/pefidopuzegad.pdfIn PDF document text
    • http://startent.ru/SITE/files/editor/file/gobogekinutena.pdfIn PDF document text
    • http://dnt-mayak.ru/content/File/57632418684.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=temple+run+christmasPDF 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_off0000bbca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBCA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d3dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3DC 17076 bytes
SHA-256: 1404c84574e254916fd3e74956a076e1e6be7e6d831ee1afabdf7601a5f82534
font_02_sfnt_off0000ffea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFEA 10584 bytes
SHA-256: bf63d68d816bd13f74f1798c0e42b3bd21c48d34f39627c9dc4a4601f8788abe