Malicious PDF — malware analysis report

Static analysis result for SHA-256 4238a41fd81cf284…

MALICIOUS

PDF

84.8 KB Created: 2021-09-04 08:29:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c384bc72ee71b274acb67b8478431b00 SHA-1: cfde391b1b1eac47a062d1a8522c4b624f39fec5 SHA-256: 4238a41fd81cf2843c53816bb697f254e65cbb0daa979f9a2d80fa9f599d3af6
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised or disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, with the PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirming the nature of the link distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://mrybalko.ru/files/8969345088.pdf In PDF document text
    • http://box8websites.com/ckfinder/userfiles/files/45339822357.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/16076eea310eaa---63920760246.pdfIn PDF document text
    • https://allianztc.ro/files/file/tekopu.pdfIn PDF document text
    • https://primer-spb.ru/files/files/tamagufomarusoj.pdfIn PDF document text
    • http://stark-tools.ru/images/uploaded/fevasetukusob.pdfIn PDF document text
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c26920c7df7---6368463262.pdfIn PDF document text
    • https://responsible-tourism-alliance.com/content_file/files/49767760780.pdfIn PDF document text
    • http://illinoislivestock.org/userfiles/file/71170067025.pdfIn PDF document text
    • http://safeabortionnepal.com/userfiles/file/jumafapotidexiju.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071b19c3766d---2558923314.pdfIn PDF document text
    • http://avs-market.ru/admin/ckfinder/userfiles/files/fudelumasigagifabadodet.pdfIn PDF document text
    • http://cuatro-pr.org/sites/default/files/file/faboj.pdfIn PDF document text
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16088bfad0bc5f---dixadumofetixatemisa.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/59f8d261645ce8526bff1835969e302a/75424254156.pdfIn PDF document text
    • http://nguyenquangcomputer.com/upload/ck/files/kisaxodudubunanagidaleti.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/0hkrhddcrjc7mlqjadjfheuon7/jojesetexowusuxi.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/zutixuxibaluxujanixilan.pdfIn PDF document text
    • http://nineslash.com/user_file/file/85520597887.pdfIn PDF document text
    • http://somogroup.vn/ckfinder/userfiles/files/59211453635.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160d902411e924---juwivoxifoxogosu.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/c72b603f4ce53e24785b60d2c00d2b2f/kurexiv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=java+eclipse+tutorial+pdf+deutschPDF 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_off0000e136.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE136 10772 bytes
SHA-256: 1a1fdd0666740937a8c71f9539cbb5783ecb06546bf9ad7f5d3c3ad8d93b956a
font_01_sfnt_off0000fa29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA29 19540 bytes
SHA-256: 20e5beecfcba874183f43ab13ee0d28ba10b907f5a8c05300bf7e01c93c4ccd0
font_02_sfnt_off00012dbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DBE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1