Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3af8318f45de8f0…

MALICIOUS

PDF

76.6 KB Created: 2021-06-19 20:05:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 28ca5c7046400d2438bd8fd38d7256df SHA-1: aebbec338f50bac26230a746c6122ce65db68782 SHA-256: a3af8318f45de8f0756b67567cc4830274395a90f0bc7f448e7d00695aaa3776
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to compromised WordPress sites, suggesting it's part of a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. The embedded URLs and the heuristic findings point to a tactic of using seemingly legitimate search result lures to drive traffic to attacker-controlled infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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=signos+y+sintomas+del+alzheimer+pdf PDF link annotation
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b79c27e8700---68210517867.pdfIn PDF document text
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/855bcd622da835a766d7699513d075bf/61848799937.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ad96f696cb9---85601619831.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c743d23dfb---23643499153.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-4-29/20210429140919123297.pdfIn PDF document text
    • http://tsg-vaganovskoe.ru/ckfinder/userfiles/files/fekewunodidi.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/5fahsqa7kg5bpjs2qethf1agh5/71600369296.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/zaregivesonosonot.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f4c9259779---karafirokitegudigeb.pdfIn PDF document text
    • http://chaitraglaze.com/uploads/2389582389.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/8dcbd3914a9a0acf84739c162edcf037/21249291496.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085eb5059b6b---57636786719.pdfIn PDF document text
    • http://xn--aknmedikal-yub.com/uploads/file/revot.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080537ff1050---gopitofiwejazetetal.pdfIn PDF document text
    • https://www.movingwithmagna.com/wp-content/plugins/super-forms/uploads/php/files/a34255489df2e77888fb9795181d2dee/32015484288.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607daffceba92---19527488975.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/160947741d5d39---68372434041.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16097312b39c58---4514904182.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_off0000eb44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB44 5712 bytes
SHA-256: e5cdf40a0abdf0737f6d2aa60e4209c8499f572727a046b44a8f98192454c255
font_01_sfnt_off0000fe9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE9D 11528 bytes
SHA-256: 4ea7cb5d0edb979fe0f60ae7ba084ffd100e2a4132ead66f10077591cb623a17