Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b879f4505f60f67…

MALICIOUS

PDF

83.5 KB Created: 2021-06-26 04:31:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: ffe4b02a42bb6baa4fb02b3aeb8d0e23 SHA-1: 2f31afd545d4e3b4c5610364421c286fc93f889c SHA-256: 3b879f4505f60f67d8aa1d7a469f16d6358f36ab09572885a5d82d6f3b12940e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged 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 upload directories, suggesting it functions as a link farm or redirection mechanism to phishing or malware sites. The presence of embedded URLs and the nature of the heuristics point towards a phishing or credential harvesting attack, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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=multiple+choice+questions+on+acid+base+titration PDF link annotation
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1607938f4acca0---52879107901.pdfIn PDF document text
    • https://kristinanamaste.eu/files/49944331483.pdfIn PDF document text
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/27d22d7765cd247b3614fca86ddb8e3b/85662623927.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1606ef787ef311---43804833646.pdfIn PDF document text
    • https://krono-original.vn/Images_upload/files/rojobi.pdfIn PDF document text
    • http://shuswapladystriders.ca/userfiles/file/74485198687.pdfIn PDF document text
    • https://jahanchart.ir/data/files/file/36145544747.pdfIn PDF document text
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca8f639149---20081673470.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bd5779869a7---nabukejojorijid.pdfIn PDF document text
    • https://magatek.com/documents/file/xuwemumetiwutitefaxaxiv.pdfIn PDF document text
    • http://broadmoor80.com/clients/866172/File/xemulub.pdfIn PDF document text
    • https://cambodiaangkorhomestay.com/userfiles/file/posadirezobejefetutomibo.pdfIn PDF document text
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/f46274b0525aa1aedd337801b8080f4f/27996404074.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/aa4eeb156f7caa0c45c1b0490bd66bcd/binivalulixalipipu.pdfIn PDF document text
    • http://bscartridge.com/pic/mazonoxumurefedajate.pdfIn PDF document text
    • https://www.ideaklinikizmir.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607174f17f5fc---nozuwaxur.pdfIn PDF document text
    • http://x04ydivan.ru/userfiles/file/22601796315.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//linul.pdfIn PDF document text
    • http://aldara-latinoamerica.com/userfiles/file/levuroxigikovexuwed.pdfIn PDF document text
    • https://wkd-uk.com/wp-content/plugins/super-forms/uploads/php/files/7f72bde3d7e6ff9f7eea17beb23f1164/52431397575.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/3knu228hsf9faa9r49hg8ermuh/meduvajawedawun.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a8aa817a00---80530069897.pdfIn PDF document text
    • https://tripleccompanies.com/wp-content/plugins/super-forms/uploads/php/files/14a03f7368146cd40c71234567b3a0b1/73885572114.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/38c8e5da2bdee8fb4bd1bbf383ca38f5/kuzokinijevuwabozipuzixeb.pdfIn PDF document text
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608fca4aaf6b6---rixirowavefemala.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_off0000e59a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE59A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fdac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDAC 15988 bytes
SHA-256: 7ec7d466676308f86a7391258bae998e87a979b601e3bf006033759db5b01f59
font_02_sfnt_off00012704.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12704 10988 bytes
SHA-256: 417a4e4bff3acccbe6ba77bfa02df8ea11549051b84b7e0d9a536547af005dbc