Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae8f0634db42d3b8…

MALICIOUS

PDF

90.2 KB Created: 2021-06-28 08:51:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b137c2efcc4d539b0d78e2aa59fce4da SHA-1: 0ea9b87d9ca469322a29c39870a53c7f7a65566b SHA-256: ae8f0634db42d3b87870b8a1a6e9d124ed2b6e4e87cabb39e0bc5620e2baaa33
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting it functions as a link farm to distribute malicious content or conduct phishing. The document body is heavily obfuscated and appears to be junk data, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://archism.ru/uplcv?utm_term=writing+task+1+structure
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7a5859e180---guwosetukelisawapis.pdf
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/t3fb7pqq1buqbh5tbscnmo5io2/sofed.pdf
    • http://arniestribu.com/campannas/file/96509618009.pdf
    • https://omomediacion.com/wp-content/plugins/super-forms/uploads/php/files/10257fd4891c3136e0244f5cf8cfb8e6/87422494023.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077354f3af92---93366128503.pdf
    • http://hoitruyengiaocodocvietnam.com/uploads/image/files/52658191470.pdf
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607ccf8dc26bd---sosamuj.pdf
    • https://olterus.org/contents//files/bemalawavaturiwukeforo.pdf
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160868fd168d02---46852863948.pdf
    • https://sindonis.com/userfiles/file/74217208290.pdf
    • https://www.straightmyteeth.com/wp-content/plugins/super-forms/uploads/php/files/7ecd182cf13fa4174e80406dd0e3d573/kelavi.pdf
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/efkd28359r1hueik37i3i5ump2/12475780010.pdf
    • http://texasstatealphaxialumnae.com/clients/f/fe/fe72632f573fdc77cca6b85875c63e8a/File/96230748690.pdf
    • https://tkquiz.com/userfiles/file/91221165098.pdf
    • http://automotiveenergy.cz/userfiles/file/59880557738.pdf
    • http://www.allatpatikapecs.hu/images/file/53499983501.pdf
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/6c73c6ecea729b763a427eb023851d47/86845610566.pdf
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073b71233c9d---8340376251.pdf
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/0j8ifhhbsvpdn79m87md61pmr1/78664280738.pdf
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a3623b80579---wovuvenikusa.pdf
    • https://gearforfree.com/wp-content/plugins/super-forms/uploads/php/files/79a9vifdocrmd0d3n26ktab01p/depiguwawowibe.pdf
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16087443f6916b---13457918870.pdf
    • http://www.aqsclimited.com/EditorImages/file/54475089728.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fe09.bin
2dee9ac7ca4c7bb11259b91f969b6baf8262a5e9c6e039123e0ff5f6bb007fd8
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE09 17368 bytes
font_01_sfnt_off00012b7a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B7A 16792 bytes
font_02_sfnt_off00014391.bin
e69458260707ac63ceed5fdce551e7b5f067dc2598811e4cf476c5104b157936
pdf-font-stream PDF embedded font (sfnt) at offset 0x14391 10476 bytes