Malicious PDF — malware analysis report

Static analysis result for SHA-256 2381a4ed84a820e3…

MALICIOUS

PDF

64.9 KB Created: 2021-06-14 14:16:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-31
MD5: 5847eb48ed83bb0440f90670d62be329 SHA-1: a97226ff9a7ff986b74d853891f73800fd4c05cf SHA-256: 2381a4ed84a820e3da16c3c534f15789311103a558c30ff4824f3dce1c2972f1
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains numerous external URIs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a pattern of using disposable hosting and SEO-related terms in URLs to obscure malicious intent.

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://krisoc.ru/uplcv?utm_term=2020+mahjong+card+pdf PDF link annotation
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/fn69k67u6s1oupi2sg9u8rn2o7/zoruxokakun.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/6tl7p42cr8vd2qssajni4d80pp/4327294903.pdfIn PDF document text
    • http://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608799895755a---36733023831.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a600efe82d9---15528985909.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/9607f28805d1bd3c52b3d942fe32a3f5/20573182605.pdfIn PDF document text
    • http://www.goldenlantern.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608ada02ea4fb---40787332106.pdfIn PDF document text
    • https://zweiund40.com/wp-content/plugins/super-forms/uploads/php/files/dguj3ab76pj21be4bv64o20vi2/sezodategupugavajo.pdfIn PDF document text
    • http://goldnumber.info/userfiles/file/fijulesuzonidijanodobof.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093bd2cecc8c---vawobavatewu.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/m9c0lojgjcsu32474k1vorck80/jijapapamawukuramametix.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/4771f174f537220d2bd6535dd28164c7/wajonujajuxuverupegajara.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/ra8i8v0q0lp3cotrjo4nfsut20/21468862874.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/16097a7a1b0931---42651543055.pdfIn PDF document text
    • http://cepsagibyachtfuels.com/images/photos/79914064200.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2713a8068b---vudegumubuzinalune.pdfIn PDF document text
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a180e6f07b6---4925452441.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_off0000c400.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC400 5612 bytes
SHA-256: 7a65fea7e9d29a71087251eeb9eb53ce47df803136932740512633f48fd5cc4d
font_01_sfnt_off0000d6fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6FB 9608 bytes
SHA-256: b776a310bcc6c5ea98926211dbe29bfb8f181f36c90f4ab458c153788bdc0f46