Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b3e12d17de5daeb…

MALICIOUS

PDF

81.4 KB Created: 2021-09-15 14:15:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 61ad51bbb4a3adcd3791a7274268cbb2 SHA-1: 86c08743cb0e5ad283d1f4c13b9c9d25f137b8cb SHA-256: 4b3e12d17de5daeba7a4361db0518336bbc068f99b9f7feabc25d304c1780742
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing to multiple compromised CMS upload storage locations and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://homestayhoian.vn/uploads/image/files/99549426666.pdf In PDF document text
    • https://butyfarm.mm520.net/userfiles/files/14747383764.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161324bd8678ec---bimikutajuloz.pdfIn PDF document text
    • https://yk-tech.com.tw/ckfinder/uploads/ckfiles/files/tupedoxinefepufibilaxifod.pdfIn PDF document text
    • http://preprod.app-nomads.com/ugecam/admin/ckfinder/userfiles/files/82997283904.pdfIn PDF document text
    • http://palakkadtourism.in/ckfinder/userfiles/files/19080440343.pdfIn PDF document text
    • https://icnj.net/ckeditor/ckfinder/userfiles/files/75612503958.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/20094807587.pdfIn PDF document text
    • https://shindah.com/images/ckeditor_img/files/xegafivovab.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/qemett7bjpb1ciklakv7m5ids4/xebubodiwexu.pdfIn PDF document text
    • http://toanlinh.vn/upload/files/vavize.pdfIn PDF document text
    • https://ilonew.tasksplan.com/userfiles/files/fixurawapa.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/kbbl3gjb1enukjn8h6pfgu6f63/lidevevesat.pdfIn PDF document text
    • https://cfi-registration.org/buzzboxgift/img/userfiles/files/2603121788.pdfIn PDF document text
    • http://anticacarsulaeborzoi.eu/userfiles/files/31108600174.pdfIn PDF document text
    • http://platcometals.com/images/file/zeloxenirolaferumivadop.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/161327863ee948---28776429231.pdfIn PDF document text
    • https://actor-conseil.com/files/file/8964058369.pdfIn PDF document text
    • https://www.tvmreza.tv/ckfinder/userfiles/files/3065217291.pdfIn PDF document text
    • http://rbtyutj01.com/userfiles/files/88859683451.pdfIn PDF document text
    • http://geoscan.it/userfiles/files/30884175017.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=cube+acr+bluetoothPDF 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_off0000d60c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD60C 19412 bytes
SHA-256: 803276c1d0e919d58d01f012df1b99ce27d45c7fc3ef07ae27c960a6d6505ccb
font_01_sfnt_off000108ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108CE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000120e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120E5 10232 bytes
SHA-256: 87cde057c182a312e3c92c27055167e8b2b8e55c0af867c4069bf5dc1f458fbe