Malicious PDF — malware analysis report

Static analysis result for SHA-256 a686c4d4b613ca89…

MALICIOUS

PDF

77.2 KB Created: 2021-05-28 22:44:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 577d9e87a47edd72f72b437ca8e8269f SHA-1: 16c7e2af6a55686cee308920b439e9aa0c4a8bb4 SHA-256: a686c4d4b613ca89b79893a3bec90ba059e20a5de5e86384bf0c84d0a3bc5a63
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics point towards a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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=descargar+libro+a+la+carga+gung+ho+pdf PDF link annotation
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/7289b4bdd0ebe03b6a155a4d62ed8c3a/zifireje.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/0q4tn2no6qt6uipnhdu3b2fs0j/golavaxib.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6f2d47cf33---jubelefuledum.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160abda0f7a1f9---sokoberute.pdfIn PDF document text
    • http://www.redactordecontenidos.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160786a7883bf7---74969257774.pdfIn PDF document text
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f13381249e---26541386446.pdfIn PDF document text
    • https://grand-forge.ru/wp-content/plugins/super-forms/uploads/php/files/0033fc0f2d05ac4bc1eb4ac7bf84b34a/gizib.pdfIn PDF document text
    • https://sasalidayanisma.org/uploads/file/sovobaxekiwubesusimew.pdfIn PDF document text
    • http://cropscipublisher.com/files/upfiles/file/96903327203.pdfIn PDF document text
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/2f48cd1996e5f4ff43eb40b38e47a1ad/ritumokiluzigor.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a38f1d090c---69814965824.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608dd1b39100f---jajopusiwixexixilowukiga.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608e6d130ac80---58841419979.pdfIn PDF document text
    • https://amerismithenterprises.com/wp-content/plugins/super-forms/uploads/php/files/9d0667466c58a0fdd32009851c3c0bed/91857037253.pdfIn PDF document text
    • http://whatdwellswithin.com/file/rijiwu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF23 5356 bytes
SHA-256: 4aa3b653947fe35fe62c769066bb7c8511d973adc8d92db01febe87db8a9dbdd
font_01_sfnt_off0000f136.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF136 11788 bytes
SHA-256: ae9a5fc28fdc79f04a6f26f67884feea3c0ee408204b7946854650d1778bf871
font_02_sfnt_off0001178e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1178E 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c