Malicious PDF — malware analysis report

Static analysis result for SHA-256 935fd070481f51ea…

MALICIOUS

PDF

68.8 KB Created: 2021-09-25 15:23:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: afc0324ee0f2b043c9960dda19833761 SHA-1: 03c72e0287c1456785ffd3c173f3b42bbc09f131 SHA-256: 935fd070481f51ea78379384c43f6dc44fc7522bb3dee81600d77358d0ca2ddc
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 https://kotypsy.pl/ckfinder/userfiles/files/zazazawimazop.pdf In PDF document text
    • http://fpempresa.cen.es/userfiles/files/luxugibimewasesob.pdfIn PDF document text
    • https://grup-insaat.com/userfiles/file/bukoma.pdfIn PDF document text
    • http://biaikatolikus.hu/files/file/zoxekananilixufo.pdfIn PDF document text
    • http://ministerium.pt/files/2705217420.pdfIn PDF document text
    • http://lynxauto.ru/userfiles/file/82902541767.pdfIn PDF document text
    • http://hit-air.pro/ckfinder/userfiles/files/9531549363.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/d42d190297ded867c97ce6bf3042f90b/8986315350.pdfIn PDF document text
    • http://officeharbor.com/pdtInfo/70780094626.pdfIn PDF document text
    • http://laboratorioshamalab.com/userfiles/file/36744072114.pdfIn PDF document text
    • http://unibox.lv/files/text/xaparegivugumilibasuv.pdfIn PDF document text
    • https://nhabe.com.vn/ckfinder/userfiles/files/1975449913.pdfIn PDF document text
    • http://www.cenlaenvironmental.com/siteuploads/editorimg/file/96215490644.pdfIn PDF document text
    • http://valdhans.cz/userfiles/file/83649895997.pdfIn PDF document text
    • https://tktravelkorea.com/FileData/ckfinder/files/20210916_ABBCB1CA7478E43E.pdfIn PDF document text
    • https://vnnc.vn/img-hdmedia/files/fanebikomeluxowovepel.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/16136a0d185e15---46235474334.pdfIn PDF document text
    • http://pepinieres-soupe.com/userfiles/file/624618014.pdfIn PDF document text
    • https://milliondollardesiclub.com/upload_files/featured/files/gukororibesuxuzire.pdfIn PDF document text
    • http://levant-tekstil.com/other_files/File/miloxumalimo.pdfIn PDF document text
    • http://minhanh.com/files/54400133969.pdfIn PDF document text
    • http://marjoleintje.nl/include/userfiles/40175323525.pdfIn PDF document text
    • http://lightofislamonair.org/uploads/files/kegegokosusufap.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140eb479c6f0---wudikivosumivu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=how+to+unroot+a+rooted+devicePDF 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_off0000aef9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEF9 10392 bytes
SHA-256: 7bcc17659a9739b9be4bc2842b0196d71b1bb500590e8f6c6df9177582985ed5
font_01_sfnt_off0000c698.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC698 15616 bytes
SHA-256: efc86642d752c057c5f9020601f0d7545585888bf4ff9259a52bab6d5f083ca9
font_02_sfnt_off0000edd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1