Malicious PDF — malware analysis report

Static analysis result for SHA-256 15c24a8151992cc2…

MALICIOUS

PDF

86.6 KB Created: 2021-09-05 08:45:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: c1c56695d0e3e96e089d1327bef5aa15 SHA-1: a36ed9f51a776932919ba2c51b98d5bbd982f5d9 SHA-256: 15c24a8151992cc20a24875d0f25e4fcd804ae49be298adc46f1956077c8cd96
96 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to numerous compromised WordPress upload directories, suggesting it's used for SEO manipulation or to distribute further malicious content. The ML classifier strongly indicated maliciousness, and the presence of multiple external URIs supports this assessment. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • 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://drafthe.ru/uplcv?utm_term=cambridge+ielts+5+reading+test+3+answers+pdf PDF link annotation
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e0c7ae31fa---76600922516.pdfIn PDF document text
    • http://atenngo.com/admin/sites/site/documents/26122226491.pdfIn PDF document text
    • http://madiagranitosilano.it/userfiles/files/2727748812.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608de2af11b16---51396696035.pdfIn PDF document text
    • https://zevkotodoseme.com/upload/ckfinder/files/26465378879.pdfIn PDF document text
    • https://rodolphe-blanchet.fr/Rodolphe/fckeditor/file/belewinirozilemakusag.pdfIn PDF document text
    • http://gamax-motor.cz/data/dokumenty/javiz.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607dfb1c7d64b---bexobusowirokufujen.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16073ea2b0729c---1401107486.pdfIn PDF document text
    • http://ottotech.center/userfiles/file/22658499817.pdfIn PDF document text
    • http://dgxzz.com/uploadfile/file/31223071008.pdfIn PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/067ede7d69fc8f409ee54de9c3f02b85/30179757686.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e5f12f41fc---dalokabagetavusumesom.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/160a3ba9b06e3e---3450611513.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160765754a335e---33923697599.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c41fafc5f0f---90253541293.pdfIn PDF document text
    • https://stephankeppel.com/userfiles/file/zesukozexigafis.pdfIn PDF document text
    • http://albatrossmrn.com/konadnew/userfiles/file/67549339306.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cc4baa4e1a---44386732246.pdfIn PDF document text
    • https://www.northwoodmedical.ca/wp-content/plugins/super-forms/uploads/php/files/bruvedebp1pt1dkmb6kpgktr6s/bibimajapadoridoneku.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b57df650d2b---pipililosopo.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0c6047a4dc---gotadabefewalujudevawegi.pdfIn PDF document text
    • https://uleiuri.ro/userfiles/file/65941939817.pdfIn PDF document text
    • http://apexhealthnutrition.com/newerac2c/userfiles/file/38280640621.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d9e4278f1---52018130151.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_off0000eb05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB05 18196 bytes
SHA-256: 190289b8ac27e9f322d76188909eb54630383f49ec871e271601741b611aa4c8
font_01_sfnt_off00011a3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A3B 11284 bytes
SHA-256: effc8a4081a50a7f52b2f8605ca7ef973eaca56aa8b04ec3debf9ab480f93735
font_02_sfnt_off0001345f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1345F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1