Malicious PDF — malware analysis report

Static analysis result for SHA-256 85d23518a37c73ee…

MALICIOUS

PDF

79.5 KB Created: 2021-09-10 14:28:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 9ce2bcefa5c56dba205323d5a3c1f64f SHA-1: 5235c67670d1bac47d011bf55991473bb475d1d8 SHA-256: 85d23518a37c73ee1ab807085b4f4190785cff9b16c1bb5cf4f5554375fe4e40
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file is a PDF with a high ML classifier score and ClamAV detection indicating it is malicious. Heuristics indicate it is a link farm and a callback phishing lure, suggesting the user is prompted to call a phone number. While no specific script was extracted, the PDF structure and heuristic firings strongly suggest a phishing or scam attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://tythb.com/uploadfile/files/73387192649.pdf In PDF document text
    • https://brothers-music.com/ckfinder/userfiles/files/rijetofabipowipisunure.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161374e85570e8---74635207964.pdfIn PDF document text
    • http://decoworld.in/dayafter/uploadimages/newsimages/file/90178067455.pdfIn PDF document text
    • http://ms2oke.com/contents/files/8236295827.pdfIn PDF document text
    • https://fanaf.com/article_ressources/file/bibolemuvig.pdfIn PDF document text
    • https://jlgardner.org/home/jlg/public_html/ckfinder/userfiles/files/kubutoboluzugixamu.pdfIn PDF document text
    • http://ptsound.com/plugins/ckfinder/userfiles/files/6680817634.pdfIn PDF document text
    • http://85560891.com/upfolder/e/files/20210910060704.pdfIn PDF document text
    • http://hkalc.com/userfiles/retavefegewex.pdfIn PDF document text
    • http://dataprint.ie/uploads/file/81749419254.pdfIn PDF document text
    • http://www.lalorraineperdue.com/documents/zobakivovopejovevamuke.pdfIn PDF document text
    • http://vaness-sens.fr/ckfinder/userfiles/files/moxijafudufeme.pdfIn PDF document text
    • https://traiteur-troyes-mariage-buffet-aube-10.blaisot-traiteur.fr/ckfinder/userfiles/files/89443398996.pdfIn PDF document text
    • http://tatishev.ru/admin/ckfinder/userfiles/files/meziresazipufimotevelis.pdfIn PDF document text
    • https://kiaavcilar.com/upload/ckfinder/files/muberonuremi.pdfIn PDF document text
    • https://pikhospital.com/ck_uploads/uploads/files/82464853816.pdfIn PDF document text
    • http://ping-property.com/user_img/files/91762282458.pdfIn PDF document text
    • http://handinks.com/ckfinder/images_store/files/nesij.pdfIn PDF document text
    • http://cold.lt/userfiles/file/88620949390.pdfIn PDF document text
    • http://traktorpulling.de/ablage/userfiles/files/ruliduvutubivon.pdfIn PDF document text
    • https://tybistanbul.org/resimler/files/likupobibedo.pdfIn PDF document text
    • http://glamour-nsk.ru/ckfinder/userfiles/files/pabedas.pdfIn PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/88861669329.pdfIn PDF document text
    • http://igigeothermal.jp/userfiles/file/jatubosadabapa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=xxx+game+in+androidPDF 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_off0000d652.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD652 10388 bytes
SHA-256: 7b36340f56495951d65548190b2c115516857dc744ba3aab65b528ba74d77ae6
font_01_sfnt_off0000ed7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED7C 16896 bytes
SHA-256: 566343bf3eae74951fccf4f51afc84a4ab627aedc0d06d5b72a6ffeec614a599
font_02_sfnt_off000118f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1