Malicious PDF — malware analysis report

Static analysis result for SHA-256 f52c528c1b45e3fa…

MALICIOUS

PDF

70.9 KB Created: 2021-09-20 09:52:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a4a4b228123699a146e85b5546270d86 SHA-1: 0c4fda52e51f16d6b483069655ca2e969bd30f33 SHA-256: f52c528c1b45e3fa62897c5aafd58500f4190631bca0c34cf714febc15ca9131
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress upload directories and disposable hosting sites, indicating an attempt to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution via these links. No scripts were extracted, but the structure and URL analysis point to a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://wcfkenzi.com/ckfinder/userfiles/files/lemurazaparud.pdf In PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614199a6ae683---22512825320.pdfIn PDF document text
    • http://susasoft.com/upload/userfiles/files/71044441331.pdfIn PDF document text
    • http://adasbruiloften.nl/userfiles/file/dorewebafotemopifotujow.pdfIn PDF document text
    • http://svazekobciorlice.cz/userfiles/file/98139604922.pdfIn PDF document text
    • http://unixsensor.com/uploads/files/202109200812527422.pdfIn PDF document text
    • http://streathamtaxi.com/survey/userfiles/files/20563801692.pdfIn PDF document text
    • https://digitaluzaktanegitim.com/calisma2/files/uploads/97079253337.pdfIn PDF document text
    • http://hairtransplantmangalore.com/uploaded_files/userfiles/files/18846494267.pdfIn PDF document text
    • https://petribax.nl/userfiles/file/febubikosidezi.pdfIn PDF document text
    • http://ecole.ru/text/images/file/nijefesefidukinalufilu.pdfIn PDF document text
    • http://fcv-bo.org/data/fcv-bo/userfiles/file/21845548397.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16140e94145694---nonixuwedoziwawakumakow.pdfIn PDF document text
    • https://nycsmindia.org/ckfinder/userfiles/files/xunetapujerejanigirusina.pdfIn PDF document text
    • https://dzido.pl/userfiles/file/89242190607.pdfIn PDF document text
    • http://telegid.tv/userfiles/files/fevujaporofuta.pdfIn PDF document text
    • https://dongphuchuytai.com/upload/files/90373004623.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/9fc9c4a637b5bf6eba32de796f0eb22a/67786876553.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/161395843f237d---77993154996.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/5460870257.pdfIn PDF document text
    • http://jezirka-biobazeny.cz/UserFiles/File/27098415425.pdfIn PDF document text
    • https://granitnet.hu/editor_up/lomiwipatifoxanifore.pdfIn PDF document text
    • https://liantoong.com/archive/upload/files/dubetuguriwedugawesike.pdfIn PDF document text
    • http://pekingtogo.com/uploads/files/31118437723.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=hide+files+on+sd+card+androidPDF 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_off0000b74d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB74D 10364 bytes
SHA-256: 174b181733b7ad72ccb5a5d33b934a99122f257b0b3a70b776d71aaaafc33a9e
font_01_sfnt_off0000cebb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEBB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e6cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6CD 15460 bytes
SHA-256: d5504213ab9489c4ddef3898a51f223f8bf677c4184cf428bf1b9bc08cff128b