Malicious PDF — malware analysis report

Static analysis result for SHA-256 31856f8977784090…

MALICIOUS

PDF

84.5 KB Created: 2021-06-27 21:47:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: af7cff6d3d6858883d9b38156f8ad64a SHA-1: e11b126128b5c7e3be652edd470e03f35e225b13 SHA-256: 31856f89777840902180881db4d4464e2cb4b1c60d7e922638acea440de0ab44
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with numerous URLs pointing to compromised WordPress sites, likely intended to redirect users to phishing pages or download further malware. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the structure suggests a malicious PDF designed for initial access via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/1608d07e1c8882---18695896526.pdf In PDF document text
    • https://jjmassociates.com/wp-content/plugins/super-forms/uploads/php/files/129fd5bb8204178093389a7b59bbeb00/27109890415.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607153d57ea20---revatowoputet.pdfIn PDF document text
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/di2ivoq0rsjised5561o355i8b/73974225078.pdfIn PDF document text
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/3a05f548e9c9512a040de9b75d66e098/66731919865.pdfIn PDF document text
    • http://odmooregolf.com/clients/e/e7/e7046aca88cfcc92de0be8f3f6b3de3d/File/97706747559.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/3bce852a7bc0120886a5f11b28835467/96845262542.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad9e5224dd9---94235386632.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/160801bcf9593a---4635390460.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/160730b13d1ff1---84880316556.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/ba51c7f9d6143b2ef486e4dca55b84b0/rivakepasatuma.pdfIn PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/j3scl78jjjh97u635efr7ptu14/magukemonosezu.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/51005286588.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/97722601639.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/ikhrna5upbr9jr704fj6pqjvo3/99233808172.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/160882f4029c7c---51514848570.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba321f48c0d---datoxamib.pdfIn PDF document text
    • https://mvpartners.be/images/uploadedimages/file/zurutapudivowenajim.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16091cc694a36b---9506673009.pdfIn PDF document text
    • http://daehwa.info/uploaded/file/31776524207.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/poxegijijeva.pdfIn PDF document text
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/fdssr4f5da89qurg5hrjlraj1s/50622802968.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=if+he+knewPDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609aed6253786---zelutubalulajipibefet.pdfIn 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED19 16800 bytes
SHA-256: e93950f4811c22afed9e1b15adc3197d5a27eca661c2d4345f63a8e8c5de53ef
font_01_sfnt_off0001186c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1186C 9652 bytes
SHA-256: bb67a1f72ad6ea0f8f170b0ab786fc9ff111592d0c0c19f58aadac0c3fb1d716
font_02_sfnt_off00012d51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D51 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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