Malicious PDF — malware analysis report

Static analysis result for SHA-256 a72cd134104f2a48…

MALICIOUS

PDF

86.5 KB Created: 2021-06-05 20:48:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 1238c1e281798b5963e6dcbd2b1544d4 SHA-1: f217135891bf5a1b6ee03632fa1db3cb8bf5327d SHA-256: a72cd134104f2a48d5f52c2109eff3fb967bd35d28bc49b33d6226013ec5b38d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or malware distribution intent. It contains numerous links, many pointing to compromised WordPress sites, suggesting it's part of a link farm designed to redirect users to malicious content. The presence of external URIs and compromised CMS upload links further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://chcial.ru/uplcv?utm_term=what+is+the+hcg+diet+plan PDF link annotation
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16080eb5a13491---lujusuzebidikujo.pdfIn PDF document text
    • http://videofilm-tv.ru/content/File/gafutitozafixuj.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/107c5ade3dd313c3d9f0940b2af4b39e/futedoroxapuxit.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608918fedd182---fimovivadubepetuvizeko.pdfIn PDF document text
    • https://www.aserspa.net/wp-content/plugins/super-forms/uploads/php/files/fkhqb64uk4kje50b75kn5c32en/99700073911.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160864a9a19457---sigen.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080a73665778---tinazalediwipizojetelip.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/2jjj5ofb16sn5t83gkcg2uo3h5/6536566974.pdfIn PDF document text
    • http://amctop.com/board_data/editor_img/file/202105231732.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/buminevav.pdfIn PDF document text
    • https://centrobrands.com/wp-content/plugins/super-forms/uploads/php/files/3e00a1ae25df247564c5e353dd28fcf0/32317307686.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bd3afb9988---12239799279.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a1e2fbe8fe---5800678635.pdfIn PDF document text
    • https://zweiund40.com/wp-content/plugins/super-forms/uploads/php/files/2sb6ui4tku151l33d3i08adr7s/52911655181.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca208e4430---48360491157.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000105a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105A2 4928 bytes
SHA-256: 71d503ca41dd36130ea694d77d2294d98af1c9493db687e0c642f4e46d01d06a
font_01_sfnt_off00011664.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11664 12624 bytes
SHA-256: 7a42b52dfcf739b6faa16e41f212b91a8d46585b55cfc63dcf86d60d02af90bb
font_02_sfnt_off00013f56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F56 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3