Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4873113f999c62a…

MALICIOUS

PDF

80.6 KB Created: 2021-09-10 07:58:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 5f2bec9b37a64b19bed26bf9cdf88dc3 SHA-1: f8df0227d06297b0edc0f469095113784c0a6d8f SHA-256: f4873113f999c62a170c5a0bc8d6d914fba8ab5b90e16232f6cfbbeeca0dc3e3
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and disposable hosting. These links likely serve to redirect users to phishing pages or download further malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://krisoc.ru/uplcv?utm_term=mod+apk+live+chat PDF link annotation
    • https://lekkermooi.nl/userfiles/file/xiriselilizugam.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a72bc9e424---54428800319.pdfIn PDF document text
    • http://gtlmarinefuel.com/userfiles/file/71059374452.pdfIn PDF document text
    • http://teewer.mn/ckfinder/userfiles/files/50553471402.pdfIn PDF document text
    • https://gedayapi.com/userfiles/file/foniwelufenefone.pdfIn PDF document text
    • http://cuacuonbinhduong.com/upload/files/kozugerugategenifima.pdfIn PDF document text
    • http://kbinteriery.cz/userfiles/file/66974595792.pdfIn PDF document text
    • http://ooexperience.be/assets/Image/files/sugif.pdfIn PDF document text
    • http://biomehl.com/images/content/files/domapibemulev.pdfIn PDF document text
    • http://vallovin.it/userfiles/files/lajal.pdfIn PDF document text
    • https://tootooair.com/FileData/ckfinder/files/20210907_143D63F4AC8AACFB.pdfIn PDF document text
    • http://eamenfaraz.com/cache/fck_files/file/vagavovogitopisenuno.pdfIn PDF document text
    • https://al-farh-iq.com/upload/userfiles/file/21883952186.pdfIn PDF document text
    • http://wsm.hk/images/files/kubopupokalubafegen.pdfIn PDF document text
    • https://hkbca.org/UploadFiles/file/20210910071531107.pdfIn PDF document text
    • http://thibangoto.com/app/webroot/uploads/files/jenabuforen.pdfIn PDF document text
    • http://hk-sai.com/ckfinder/userfiles/files/99664487125.pdfIn PDF document text
    • https://ashasuchikala.com/ckfinder/userfiles/files/3603742551.pdfIn PDF document text
    • https://piataafacerilor.ro/app/webroot/files/userfiles/files/sapixaxetelazamurora.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/ff6d92a1566f3417b8b181af4614a1f3/72513752687.pdfIn PDF document text
    • http://draftingfloorplan.com/ckfinder/userfiles/files/89374552857.pdfIn PDF document text
    • http://www.icf-plant.com/files/file/supufanubofe.pdfIn PDF document text
    • http://tfforming.ru/d/files/wuperebebanikitaweramodo.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1612efa9b51665---wodomupisinogibuluwokuze.pdfIn PDF document text
    • https://hoya.hr/UserFiles/file/4818944879.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139e5d4af51e---fufejikupopelupujiloj.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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d6ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6EA 10388 bytes
SHA-256: 9a07702f65aa5a18081023a7a614fb2f4f86af9459cda2c6062ae3c1d2ffa8b9
font_01_sfnt_off0000ee88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE88 17872 bytes
SHA-256: 2004ea7cf5b7727623b8ae089e391d27d9b54bd48dd26c384419af06e252e310
font_02_sfnt_off00011ce4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CE4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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