Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb99c4f3b07f12b3…

MALICIOUS

PDF

76.7 KB Created: 2021-05-17 13:55:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 12af0f6776916d99d1f91250e277d2a4 SHA-1: 1da6f66730768ca52efa1fba9912b5b255bc35b4 SHA-256: cb99c4f3b07f12b30adc9a7fceb3dabc6c7aae2c02ed5e3cec2c8029358d0b2b
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites. The ML classifier strongly indicated maliciousness, and the structure suggests a link farm designed to redirect users to potentially harmful content. The presence of 'utm_term' parameters in some URLs indicates an attempt to track user engagement with the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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://nomylo.ru/uplcv?utm_term=ssc+stenographer+2016+question+paper+pdf PDF link annotation
    • https://blueridgelightingandcontrols.com/wp-content/plugins/super-forms/uploads/php/files/df8aedffeafc7c781029ccc6b85b1b99/vikigewonituxadagatofi.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d46b13d410---88418581761.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/160927a15db6f3---52008616670.pdfIn PDF document text
    • http://profisystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607347ee8aff7---52789379797.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cf5696e7c7---tumepagul.pdfIn PDF document text
    • https://cedarcreeksauce.com/wp-content/plugins/super-forms/uploads/php/files/5e896ab3be35a06792575b844ac34cab/nanodoro.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160927d1a236a7---kekajanafisixisoja.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/3281fb6ac29e0f403236873cd5fca524/25188516565.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/rubomofipikanepovadebusaz.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606e44ea9b258---53426729523.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/9kmu31eqqt5b90hmm4egrf34t0/badanosuponilufo.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099b2b6876c5---nuroxenexilixowulubofa.pdfIn PDF document text
    • https://ethiquedevelopers.com/wp-content/plugins/super-forms/uploads/php/files/8ed121bad7ed3b95c4931356e80c3a06/wukumofepimilivovij.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/16091303c98b36---pusakapokes.pdfIn PDF document text
    • https://myveolife.com/wp-content/plugins/super-forms/uploads/php/files/ac88446834645e7f81409be58220a40b/filidujodurimizogixulinav.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/160726430bbbdf---35379954022.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/c4a07b7e23e16fa526d7ea432ec94b2e/29519850756.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160933eb3990c8---40700869959.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/160780438941d0---jasogoxedo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fedorahosted.org/lohitIn 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_off0000d7d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7D9 6096 bytes
SHA-256: 7fbb1c747cdb318aea18db7c647659845ef5212b6589ffc331990bb601495050
font_01_sfnt_off0000ec8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC8E 10996 bytes
SHA-256: 3c9c1a11b3e3bc3de034bf572ac2bb7435316fa51687569210257d5dd609c5d4
font_02_sfnt_off0001120e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1120E 5256 bytes
SHA-256: 295b3936d8299b8b64116a019f9da20e9a209561c60b80c1fb1363ac4d9223de