Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb623d7edcfba9f5…

MALICIOUS

PDF

75.1 KB Created: 2021-06-16 19:53:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 18de9f54740edce86494752413e747a2 SHA-1: a64114270b2dc67654856bbc1ceb414ae9664053 SHA-256: cb623d7edcfba9f509ffa587ca15ce051b68cb88a45f7e52e7cd5d035f761bb2
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the nature of the embedded links and the PDF structure point towards a common tactic of luring users to malicious sites.

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://cructi.ru/uplcv?utm_term=a+serbian+film+watch+online
    • http://allaboutdowney.com/userimages/sifilolimalosanubawefizak.pdf
    • http://cobansut.com/userfiles/file/vuwawivikubumexetofire.pdf
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ad93d152aea---11457721915.pdf
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607e568934983---81292351628.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607a6099f07fc---43355835276.pdf
    • http://www.annaleehuber.com/content_files/file/mifutamojikepakodok.pdf
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3a66a59ff---zosifowagivurazidubidoruk.pdf
    • https://cecprint.com/images/file/sisasojobudewomurorekap.pdf
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/c618fd2fb9170075df1d4b71c5602fc0/2821422507.pdf
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2473440cda---forebawipote.pdf
    • http://fresh-j.info/images/uploadedimages/file/sudufamurojewuwizesa.pdf
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606efbb7d6d3a---tavalifikujogetasovi.pdf
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/6tdk6rp72orn52bf4vu9blngi0/69003015317.pdf
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/deb42ed452cf84eda679df85cb535b7e/36479905175.pdf
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/b67b3ead93594d6e854f3f18560ead72/69178993574.pdf
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/a756c4e06ac4cad779f1405fb66b9be3/vuzisiniboworisib.pdf
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/hqkv9jfpf28hm97ko67r70iar1/denukav.pdf
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/vgmb5upq5tllspfek7n864khap/lizifopadixadabati.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e713.bin
20c75fb5dd07a852a55171071e3949754bda6e361f226a1d835b6f21d016d93f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE713 5344 bytes
font_01_sfnt_off0000f928.bin
ae6b2f334de79a661e69aef13cbcb29b48ec52a64b8adecc620cd2b4d4c5b140
pdf-font-stream PDF embedded font (sfnt) at offset 0xF928 11200 bytes