Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca0cae04b23e58cb…

MALICIOUS

PDF

91.2 KB Created: 2021-09-17 15:20:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 7bbb873851e7361914b43cdb5fae95c7 SHA-1: 036bd5f8624aa7ff6dd68aa39de2999c0b5ab5ae SHA-256: ca0cae04b23e58cb5012fb192d77814894f29e047759261eec17e29d57f904a9
126 Risk Score

Malware Insights

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

The PDF sample was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of numerous external URIs, many pointing to disposable hosting and employing UTM parameters, strongly suggests a link farm designed to redirect users. This pattern is commonly associated with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://laborke.ru/uplcv?utm_term=shareit+android+download+apk PDF link annotation
    • https://stomatoloska-ordinacija-rijeka.com/files/71030413936.pdfIn PDF document text
    • https://www.natursany.com/ckfinder/userfiles/files/suxixokedakimoranutek.pdfIn PDF document text
    • https://studybrilliant.online/app/webroot/img/userfiles/file/fomuwaxisovevikiromijivus.pdfIn PDF document text
    • http://forspeed.cz/ckfinder/userfiles/files/fakijanaduraje.pdfIn PDF document text
    • http://dgjst.com/upfile/file/52189856497.pdfIn PDF document text
    • http://jingmingtai.com/filespath/files/20210901233213.pdfIn PDF document text
    • http://archetipoingegneria.it/userfiles/files/xavopizumemipalikeg.pdfIn PDF document text
    • http://tuzy.pl/Upload/file/77138118299.pdfIn PDF document text
    • https://bdaudit.ro/userfiles/file/folunogogitamuvebexu.pdfIn PDF document text
    • http://vimbark.sk/editor_uploads/files/tuwupom.pdfIn PDF document text
    • http://auburn-properties.com/userfiles/files/kunaxegozarul.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16141fc0559590---72252523781.pdfIn PDF document text
    • http://freetourscadiz.com/ckfinder/userfiles/files/repunonizirobebexim.pdfIn PDF document text
    • https://ferado.vn/userfiles/file/84332680086.pdfIn PDF document text
    • http://intemhathanh.com/img_duhoc/files/16166306506.pdfIn PDF document text
    • http://kondicionery-domodedovo.ru/upload_picture/file/24194310423.pdfIn PDF document text
    • http://travellerisland.com/files/tirudutugiruxerupenudimub.pdfIn PDF document text
    • http://trustycctv.com/ckfinder/userfiles/files/5304871431.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16141e85a7a877---35393016653.pdfIn PDF document text
    • http://realtor-madrid.com/uploades/fckeditorfile/wiwitadizopiwuburavodu.pdfIn PDF document text
    • http://stroyindustry.com/userfiles/file/32233510086.pdfIn PDF document text
    • http://dachastyle.com/userfiles/file/76887985992.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a114034548---90488708500.pdfIn PDF document text
    • https://toananhmedical.com/uploads/files/siwineve.pdfIn PDF document text
    • https://riminabda.sk/userfiles/file/61621528642.pdfIn PDF document text
    • http://kbcsisa.com/upload/fckeditor/file/51415801436.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_off0000ff20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF20 18160 bytes
SHA-256: b50b16bdc8d51bcd43231add2254f81aa2958a3272d89d247309168859a809a6
font_01_sfnt_off00012e99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E99 10576 bytes
SHA-256: 049a039298b4750811b5aa38ce9b7618c5dd8a0f9a8e75fd7a4a20db44fd98d2
font_02_sfnt_off000146b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x146B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1