Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b8f279b89552fa8…

MALICIOUS

PDF

83.1 KB Created: 2021-09-20 01:17:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 0f91d62ef91492ed7339ccb85dfc7da6 SHA-1: 5a53c98a6ca53b342a8d9a2773a23a7c2e0774c2 SHA-256: 3b8f279b89552fa834099ba9b7af997fc36c346a0510d452638c43b6f1b096fa
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to multiple compromised WordPress sites, suggesting an attempt to distribute malicious content or phish users. The presence of numerous external URIs and the 'SEO_DISPOSABLE_LINK_FARM' heuristic indicate a deliberate effort to obscure the final destination and potentially evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://exima.kr/userData/board/file/mejufi.pdf In PDF document text
    • https://sportyou.fr/ckfinder/userfiles/files/81827300862.pdfIn PDF document text
    • https://mmrh.myagenda.cz/pictures/editor/files/60219753718.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/161324a73c2125---lidebe.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/08d4e66915408223ec40fb894068ef3d/72846764736.pdfIn PDF document text
    • http://flairpens.ru/uploads/file/80563669864.pdfIn PDF document text
    • http://www.weilandensemble.nl/ckfinder/userfiles/files/13592947637.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/76vk05vf1tgebd703rsp6uqor7/jigujememinatafedix.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/3c7dfba8e537f06367da8fd6bd5e638c/43964261358.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16141432243e58---tupowusawuguvitomiba.pdfIn PDF document text
    • https://vialivonica.eu/userfiles/files/50370840537.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147a57c9c548---91083839704.pdfIn PDF document text
    • https://buonoantonio.it/userfiles/file/rebunifadubirabado.pdfIn PDF document text
    • https://cooperadora.grupocreartel.com/documentos/archivos/sopafe.pdfIn PDF document text
    • http://www.vako.vn/app/webroot/uploads/files/vazenofuwupuludejexuku.pdfIn PDF document text
    • https://sharkovinkom.com/sharkovinkom.com/ckfinder/userfiles/files/89914398340.pdfIn PDF document text
    • http://szyqjsj.com/UploadFile/file/20210919023405525.pdfIn PDF document text
    • http://www.sandipmallick.com/fckimages/file/53151645373.pdfIn PDF document text
    • https://tuoitre.bacgiang.gov.vn/lib/ckfinder/files/pezazutegebarude.pdfIn PDF document text
    • http://bjsixiang.com/jingkelun/userfiles/files/20210906140811.pdfIn PDF document text
    • http://costruzionibulagna.it/userfiles/files/fepagabuxuzuziruf.pdfIn PDF document text
    • http://www.gpkoaee.ru/ckfinder/userfiles/files/nugipasabusop.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/ji8vatjo8dgq4qmmepv60fbn64/78548361020.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=watch+english+movies+online+hdPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e05a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE05A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f86c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF86C 17680 bytes
SHA-256: c3fb1d649414a733151d919223744b59c1cf3712cbd249bb0e69dc34a99be395
font_02_sfnt_off0001266c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1266C 10776 bytes
SHA-256: b2a57866611d7644999232bec83fabfee519cd5999992a0a7885189504fb3a46