Malicious PDF — malware analysis report

Static analysis result for SHA-256 23913d9b4642f647…

MALICIOUS

PDF

110.9 KB Created: 2021-06-25 22:16:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 4bd9b4ea3da3200e63e575d1921dc5dc SHA-1: 8e3ec866a65aeb0a0e3128bcf86e1fdd52b6848e SHA-256: 23913d9b4642f647962dcc4ab15dd12622af49092d21d1ffc22720c91384e82d
156 Risk Score

Malware Insights

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

The PDF file contains numerous links pointing to compromised WordPress upload directories, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of multiple links on potentially compromised CMS platforms points towards a coordinated effort to host malicious files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/160878017cbc87---57525911392.pdf In PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/6d25fb724cd5cbc63c57b0e4da8b58cb/digirezululotijo.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b4d7dbee11---16847242160.pdfIn PDF document text
    • http://udemadriatic.com/userfiles/files/14019874657.pdfIn PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609db9dc2b2c8---58243908448.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/4480af41341069114664b9860aa4f182/44386614982.pdfIn PDF document text
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/ea2b40c23f67cd975e908559381829e4/44104241734.pdfIn PDF document text
    • http://megat.pl/uploaded/fck_files/file/12589391325.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/036d98f64110d918cabb216c0cbb85da/xosupapegibexu.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cc3b2f8f798---tepifimawa.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609425b59779f---42925181380.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/rceufike2lsenctj3fbhfjvdj1/nizalufagikafi.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a772cc07a12---35190156084.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/524f10ed576ebe9bb39f51aa63dbcd94/wetotufeziwenejagogag.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/1607a5373935de---87036539103.pdfIn PDF document text
    • http://photographybynami.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098ba346cc85---vuxewosej.pdfIn PDF document text
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/n09mchpubhrcr72f8sml1fvu8r/lefaper.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/bajesobeba.pdfIn PDF document text
    • http://nt-module.ru/ckfinder/userfiles/files/77271310290.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077adbb5ac27---57412257537.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f6db08dd8e---xumafaj.pdfIn PDF document text
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160799033ccd2d---newelemuxokusefowanif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=1997+ford+mustang+cobraPDF link annotation
    • 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_off00014feb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14FEB 17204 bytes
SHA-256: af42916d1b46a83873aa93746a8f5c9c2cf5f5eb8f0a31dd54546cf883d92b0d
font_01_sfnt_off00017d2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17D2E 10964 bytes
SHA-256: be805b4e066a78476045039ce66ead9e2f9626a803dad067a71ace830446ff11
font_02_sfnt_off0001968e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1968E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1