Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1acfb951d588bb4…

MALICIOUS

PDF

76.7 KB Created: 2021-06-09 16:53:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: ba8650e319858f607356bbaeb10be8f9 SHA-1: b7a23cde6191f6676e98b0a7a3c669942f62b2a8 SHA-256: d1acfb951d588bb4b0eb398f88539cb978ee2a5bde83339bd92ba4a523fe962e
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and links to compromised WordPress sites, suggesting it functions as a link farm for phishing or malware distribution. The document body is heavily obfuscated and unreadable, but the presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM heuristics points to a deliberate effort to obscure the true destination of the links.

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://medvor.ru/uplcv?utm_term=vapour+pressure+thermometer+working+principle PDF link annotation
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/45df0881a190ba313f29a922ff5f2d59/72305882041.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074fbd2bda15---32474399807.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a7375fe0826---kivukigotovulu.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/a10144025a937584e575c63bc84bd1ef/40968348423.pdfIn PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/8eaf05149a60114d131bed2ff4e030e6/bogoreligofitumalunagol.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/16077f051764fc---xebagaf.pdfIn PDF document text
    • https://abugfreemind.com/userfiles/file/rotebunujivodibeb.pdfIn PDF document text
    • http://xn--clinicaquirogavilario-vbc.com/wp-content/plugins/super-forms/uploads/php/files/tromo9egd8jvcdn287ai1tqv43/wavowopuwadofesove.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/8974d374c091b7c832e0b7875a5b74a0/wixetep.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/a41c52a9edd270828355b5341fa5e2fb/bizobemibo.pdfIn PDF document text
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/46f9821c394c146ac2cc848dc0f6a64a/67119728801.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160828c7e04ece---90770476231.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606d5be316a12---3411655743.pdfIn PDF document text
    • http://korean-school.hu/hangul/userfiles/file/77809174049.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_off0000ef62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF62 5468 bytes
SHA-256: 3c2ffaa4d6c442aa01a8d2dc78234ebbbdc3930e3f60f813b0cad52d4be6c98c
font_01_sfnt_off000101f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101F0 10908 bytes
SHA-256: 8cd9f49f271109fe4b8ff296a801aaf06c547c25459fd54301a3a4da92e43fff