Malicious PDF — malware analysis report

Static analysis result for SHA-256 121ef9ac399810e0…

MALICIOUS

PDF

68.5 KB Created: 2021-09-14 10:19:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4f85b4cefe14db7d277aea78cf679423 SHA-1: 0a74d2afa733e0aa0394cabd63c53afa54a872e6 SHA-256: 121ef9ac399810e0087dfb25cbf54fe09f3cc1d6fafbb8dcd67148b1143db031
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://medvor.ru/uplcv?utm_term=gta+san+andreas+in+android+download PDF link annotation
    • http://alpanelektrik.com/depo/sayfaresim/file/vimudemuwuvexaruxopilo.pdfIn PDF document text
    • http://energosol.pl/images_cms/file/79534718902.pdfIn PDF document text
    • https://ph2020.org/ckfinder/userfiles/files/jokukikap.pdfIn PDF document text
    • https://oriontradecom.com/ckfinder/userfiles/files/lewizawiroxosufilezukuwi.pdfIn PDF document text
    • http://tehpromyar.ru/media/file/rawufuwaruduxiximeka.pdfIn PDF document text
    • http://adice-area.com/pictures/files/mafejojupomuwotujesewat.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/gpp93gu0qlht6eu28mtmvmf864/59320741651.pdfIn PDF document text
    • http://londonjip.com/userData/board/file/51294593814.pdfIn PDF document text
    • http://www.northern-japan.com/image/upload/File/xifafavekedib.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eed3c9e2ec---44255358016.pdfIn PDF document text
    • https://actor-conseil.com/files/file/jevelokolisezepujoxif.pdfIn PDF document text
    • http://jfhcoaching.com/userfiles/files/sebeziguvuxubaxiv.pdfIn PDF document text
    • https://valubil.com/public/uploads/cms_file/cms_files/pimabapofemeri.pdfIn PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/vadeparatewodefabupixidop.pdfIn PDF document text
    • http://xn--b1afklwjc5g.xn--p1ai/ckfinder/userfiles/files/lalabakedumafosogulim.pdfIn PDF document text
    • http://www.farmaciavictoriayjmleon.com/userfiles/files/gopibovufozi.pdfIn PDF document text
    • http://tries.cz/media/images/upload/file/55743359686.pdfIn PDF document text
    • https://nbcmedia.vn/ckfinder/userfiles/files/20509796179.pdfIn PDF document text
    • http://byecook.com/ckupload/files/rerarowipipadurena.pdfIn PDF document text
    • https://duongthuy.net/userfiles/file/23061075330.pdfIn PDF document text
    • http://aptekarynek.pl/zdjecia/fck/file/54714515788.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/161306f98cf882---kevulitepesasakem.pdfIn PDF document text
    • http://opusincertum.it/userfiles/files/padijazepixorefomi.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_off0000b0be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0BE 10368 bytes
SHA-256: b825c0ec3c2a1059058b4c48a18d5ba47b14c3efc1f0758eaf8f14daf978b57d
font_01_sfnt_off0000c865.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC865 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e077.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE077 14304 bytes
SHA-256: 8d08d84ed3b2e2b34248268dde7a08d806988b9606752807824aa69276e5eff1