Malicious PDF — malware analysis report

Static analysis result for SHA-256 57d37c1c96e060ff…

MALICIOUS

PDF

85.2 KB Created: 2021-07-07 07:27:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: e5db729d82b796f440df0d041ec34b9c SHA-1: 468ffea504dd7c54be13eed2b64e8fb4b3290be2 SHA-256: 57d37c1c96e060ff0ef16e286f50d11d5094c2aedde25e3bbebb9a267ab15682
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The presence of multiple external URIs and link farm heuristics supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://anhuizhkj.com/upload_fck/file/2021-4-30/20210430225546999896.pdf In PDF document text
    • https://glycocalyx.nl/userfiles/image/file/92983422718.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/e11051ff8027620eeda893588d9d9d2d/jodis.pdfIn PDF document text
    • https://akvaguru.hu/user/file/44099770046.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c22531ea559---10258361019.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/8337039b838b261f33ad7efe20c4ab4e/tamuzunan.pdfIn PDF document text
    • http://championshipsportsrings.com/clients/23492/File/bibopozepasowuxajutiru.pdfIn PDF document text
    • https://iwanbim.com/userfiles/files/96851663664.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b7bd681e98---mikedunidezogoxipatupag.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/2021722321221800.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/cf6st9429ivc08rjej6g1qkm81/gibewake.pdfIn PDF document text
    • https://rittenhousesmiles.com/wp-content/plugins/super-forms/uploads/php/files/a57edade950fb146d576bc5adaf45953/25052466420.pdfIn PDF document text
    • http://szpk.hu/_user/file/bubewefewezigifirarimo.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/2rqi9jub6vt8411h6cg5epi196/niloduwadubated.pdfIn PDF document text
    • http://densayhongngoai.com/uploads/userfiles/file/bolumexawi.pdfIn PDF document text
    • https://ecole-anglais.com/upload/files/lutonojowipil.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/9780439189.pdfIn PDF document text
    • http://medica-brno.com/files/37087832540.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072cba0151a7---74030757493.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/1dpdpgecdnkh7l3p5acq9rnf62/resamefikowabosujajure.pdfIn PDF document text
    • https://www.frankreich-ferien.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160805462714ed---89143137456.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/da0aa7cb2fcb34f8fcb7fe0a707d71dd/zegisotamivomisononese.pdfIn PDF document text
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/2bdf070c9bd37f436eac46538276729d/95772642179.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=dating+a+man+with+kids+and+feeling+left+outPDF 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_off0000eb68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB68 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001037f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1037F 10980 bytes
SHA-256: 59ffca08bff353b0cacc690a7d507e7eaa1f352d983bde8c8407e39ad49654ec
font_02_sfnt_off00011ca1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CA1 16012 bytes
SHA-256: a9f95f58dbbba6b78be66d9396e609e1d785dd520d86d816cc4e86fd6c91fa7a