Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a85962aa3d13f19…

MALICIOUS

PDF

83.2 KB Created: 2021-06-12 09:03:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: 494af84e6211e1808ab871ecbbfdb767 SHA-1: 5ac320ddcbcbb172c3218d1b1c7b7ae5aaf74c2d SHA-256: 4a85962aa3d13f19c7b25a6db2f85fb0a540192fa789bf8e37c67a9824bd88c6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The sample was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to compromised websites, suggesting it functions as a link farm for phishing or malware distribution. The presence of embedded URLs and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly support this attack pattern.

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://allytemp.ru/uplcv?utm_term=example+of+two+syllable+words+with+short+vowel+sounds PDF link annotation
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/d16fd90a6c22ecc624ae8f1706c9acde/67611721813.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6ebf1665be---basetelevebumubipinavelu.pdfIn PDF document text
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/2115280c7c7f794d0d75ce966ed8ad35/lebekojex.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/6033f2beaa8953a9e02f789d6f6b2cc6/bomejejugexokaxunamur.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16093c3cfb02f9---78754544839.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e73efc56be---90166855749.pdfIn PDF document text
    • https://cupanghitam.com/contents//files/kowasonabamab.pdfIn PDF document text
    • http://tamlaproject.com/userData/board/file/56084578094.pdfIn PDF document text
    • http://kelvista.lt/images/files/9544253175.pdfIn PDF document text
    • https://vidolamerica.org/wp-content/plugins/super-forms/uploads/php/files/4c553bfd60689f05169c848ad459b174/fudedaser.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c1b4e213aee---81986107044.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160afa6a77bb34---figogekuxijemagozatagezux.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/e2d75cf0f1746c0565293471f8e972e5/livav.pdfIn PDF document text
    • http://prof-cosmetics.com/upload/files/12983752636.pdfIn PDF document text
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/vcsjgab2rs8rqi75jc3hbch753/57287530533.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fed0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFED0 5700 bytes
SHA-256: c7556d5ec9b79fc51c1892d7d7aa139a032d3d63997a0d3d468a9b7bc7906eab
font_01_sfnt_off00011222.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11222 13868 bytes
SHA-256: 9d9a996bce455ec91e529f35a4e71c369b8685e02869df044e5257ceca7c8594