Malicious PDF — malware analysis report

Static analysis result for SHA-256 53c6130f54c89038…

MALICIOUS

PDF

76.1 KB Created: 2021-08-25 09:19:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 9d182e23b15f9f5130398e1e6e7389b7 SHA-1: 1266c2a9ccd845824bdc5997ce8a8a430e467d13 SHA-256: 53c6130f54c89038445a6c98e5c89e080c07fa3d2ce6314e1f9ef97715b60c59
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that function as a link farm, directing users to potentially malicious websites. Heuristics indicate these links are often hosted on compromised CMS uploads or disposable domains, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://catamma.ru/uplcv?utm_term=cardiomyopathy+ejection+fraction PDF link annotation
    • https://sanipacific.com/attachment/file/77466723285.pdfIn PDF document text
    • http://bona-agra.pl/Upload/file/6864929030.pdfIn PDF document text
    • http://caopump.com/admin/userfiles/file/8663348945.pdfIn PDF document text
    • http://impressivetravelvietnam.com/upload/files/28016527674.pdfIn PDF document text
    • https://matrixx.lu/images/turosubebin.pdfIn PDF document text
    • https://arichaindia.com/userfiles/file/66911454667.pdfIn PDF document text
    • https://ykitraders.com/UserFiles/file/nenod.pdfIn PDF document text
    • https://moulindelarroque.com/userfiles/file/litutebazezorakab.pdfIn PDF document text
    • http://lenosada.sk/editor_uploads/files/rofarowoxarapasi.pdfIn PDF document text
    • http://medi-sen.com/files/files/86818424247.pdfIn PDF document text
    • http://zulassungsservice4you.de/bilder/file/37400204009.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/63ff1ba050e2ad92c3661b2948795b6e/49529194508.pdfIn PDF document text
    • http://www.eau-msu.ru/ckfinder/userfiles/files/nepidalemoxewubar.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a7241cb1ef8---38666353256.pdfIn PDF document text
    • http://www.schule.havonix.com/ckfinder/userfiles/files/lobezazatopeluko.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074a6b5a81b8---49653174108.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609798370996b---tinopixoronur.pdfIn PDF document text
    • http://kancelaria-perfect.pl/app/webroot/media/files/60857844684.pdfIn PDF document text
    • https://ikuseikyokai.jp/ckmedia//files/87937628402.pdfIn PDF document text
    • http://foto-klub.dk/userfiles/file/21227118102.pdfIn PDF document text
    • http://www.alfapilates.pl/upload/file/dirinusajiwugonidak.pdfIn PDF document text
    • http://angelascanu.it/uploads/file/fewexidasotife.pdfIn PDF document text
    • http://duancanhotot.com/upload/files/71860689362.pdfIn PDF document text
    • 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_off0000c76d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC76D 16140 bytes
SHA-256: d550f4fa81dd30d7fbb7bc48da0670080bd523293c3394bdcd97c74bc3317903
font_01_sfnt_off0000f11a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF11A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010931.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10931 10948 bytes
SHA-256: 5f197ef4df47e7e25a63ea976ad2b583f26a0cbccc21ef39a8309100a2e2c5a1