Malicious PDF — malware analysis report

Static analysis result for SHA-256 105a6b40b7edae1f…

MALICIOUS

PDF

97.4 KB Created: 2021-06-25 12:49:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 2b4da7e7499e38e0510443ece128aba7 SHA-1: 838b9a08d351568138e1f51ec8b3fda9341d4cc3 SHA-256: 105a6b40b7edae1fa5c83d3c77601ddae360b235bdefee434a6d14972166c196
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised WordPress sites. These sites host PDF files, suggesting a multi-stage attack or a distribution network for malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9931

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://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609464541b275---nugafukiv.pdf In PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a50e4193980---95065904403.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/5d576e91e39eb6e7bc96171067a5ead8/zexusefo.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160a71ffe0e6b2---vurevosixubenidepi.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160960f255a5fb---korimazerita.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072a61c8f4d6---difafimexan.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607f92a23db3f---fomofotanikimurasexurewug.pdfIn PDF document text
    • https://chpcentre.com/files/file/51325455804.pdfIn PDF document text
    • https://isleo.com/i_photos/file/95816285919.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb5f6691080---nebigodagularetuxuboxam.pdfIn PDF document text
    • http://cuahuyhoang.com/media/ftp/file/kipizajaru.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/f4a908627613f2be58ba00d6f7ac57da/resupixisuruzuteg.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/8cciv13s47t664f73d6kd8sst4/dafutolov.pdfIn PDF document text
    • https://sasalidayanisma.org/uploads/file/bazutiven.pdfIn PDF document text
    • http://afgventuregroup.com/cfiles/file/sebenamujinerikeru.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=the+meaning+of+spearPDF 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f085.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF085 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001089c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1089C 10624 bytes
SHA-256: 29b0ac2cad14a928013193b706da1f27530033a6e16f1f58424740c01acc9743
font_02_sfnt_off000120a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120A8 1884 bytes
SHA-256: ff755bd90c0cb538714d4951a4bef51bc324c60e74489ad92a3e9a94fa170fb4
font_03_sfnt_off00012964.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12964 17200 bytes
SHA-256: 60d9a6f0445855af773168be0a92fa8d723b8e8bfc02035b48355876c57c7c8c
font_04_sfnt_off0001428f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1428F 20128 bytes
SHA-256: 8cdc3cbfdd83a790eb77930a681b05a24ee733db359de011f543398f6883a585