Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b153072a0f27456…

MALICIOUS

PDF

80.7 KB Created: 2021-09-21 18:18:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 8d6d30c38e0ef53a9ba1c2e5f8472c21 SHA-1: a5e220847af4feaca1e0468919e979bce78df137 SHA-256: 4b153072a0f274569f0c2bfae4a1a448a8ef30729d3bc081a69c63fdd260556a
156 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 CMS upload directories and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/161425ec9ad891---duwesa.pdf In PDF document text
    • http://esrafisek.com/images_upload/files/72234022118.pdfIn PDF document text
    • http://25630638.kad.tw/kads/ckfinder/userfiles/files/81714758663.pdfIn PDF document text
    • https://selapro.com.au/application/third_party/ckfinder/userfiles/files/47365843459.pdfIn PDF document text
    • https://jdsliquorlocker.com/nbloom/fckuploads/file/63430998119.pdfIn PDF document text
    • http://namngonviet.vn/user-/files/28760237997.pdfIn PDF document text
    • https://thepainter.asia/upload/files/koxus.pdfIn PDF document text
    • http://startent.ru/SITE/files/editor/file/komajosexijugaporededavi.pdfIn PDF document text
    • http://sculecuacumulator.ro/app/webroot/files/userfiles/files/60161493897.pdfIn PDF document text
    • https://mama-light.net/business_school/uploads/file/lafefatobuxozujejosuj.pdfIn PDF document text
    • https://alstar.uz/images/shared/file/64448660440.pdfIn PDF document text
    • https://weboonline.com/ckfinder/userfiles/files/63061284574.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/161422f0589e73---nonasuvujojoz.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/161417eefc14d1---65942092148.pdfIn PDF document text
    • http://flirtproducties.nl/ckfinder/userfiles/files/vigukofozezodimewo.pdfIn PDF document text
    • https://qualityroofinnandsuites.com/nbloom/fckuploads/file/paradu.pdfIn PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/5d6666fac4c53303420add42cbdb484a/sowesupamavuxokotofogaj.pdfIn PDF document text
    • http://flyingfish-stay.com/userfiles/file/89765840445.pdfIn PDF document text
    • http://jinwoosmc.com/userfiles/file/3479079789.pdfIn PDF document text
    • http://malovanesklomh.cz/images/file/75757391917.pdfIn PDF document text
    • http://knshzj.com/CKEdit/upload/files/bixosokozoko.pdfIn PDF document text
    • https://dermatologie-francophone.com/userfiles/file/87571130333.pdfIn PDF document text
    • https://webhosting4.net/media/file/17099573197.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=john+wick+parabellum+assistirPDF 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_off0000d432.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD432 18312 bytes
SHA-256: 6321d6db8e012bf4ae9fdb444bee730647bd8361d97b3ab2ea81530710370899
font_01_sfnt_off000103e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103E5 11048 bytes
SHA-256: 0fe1ccccc373545af0667421b8ea0d704b5fb3cb42e392a40160e6f63e677eed
font_02_sfnt_off00011d51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D51 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1