Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5af616850dab74b…

MALICIOUS

PDF

93.1 KB Created: 2021-09-12 10:11:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a823a22fcd8309c945e0d93bc25e7872 SHA-1: 158705d39485ac517d6c4400614456b788fdb74c SHA-256: b5af616850dab74bbfd2ac0b05819e1bcae1e8f427485afecef575457a4809e8
196 Risk Score

Malware Insights

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

This PDF document was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The 'SE_BROWSER_INSTALL_LURE' heuristic strongly suggests the document's purpose is to trick the user into installing a fake browser update or extension. While no scripts were directly extracted, the presence of numerous URLs, some hosted on compromised sites, points to a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://tincorner.vn/uploads/files/42521387356.pdf
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132264e957fe---49701702614.pdf
    • http://studioarchterreni.it/userfiles/files/79769993658.pdf
    • https://tabularasa.lv/sites/tabularasa/uploads/documents/files/7629790760.pdf
    • http://sensor4you.com/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/5684597550.pdf
    • http://dryoucosmeceutical.com/userfiles/files/33498396158.pdf
    • http://istihdamhaberleri.com/upload/ckfinder/files/66536048251.pdf
    • http://kunbot.com/upload/files/39757285159.pdf
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/tmp/fonesepaduxivudozazew.pdf
    • http://onlytech-tunisie.com/userfiles/file/63203225440.pdf
    • https://synersys.fr/contenu/file/mesivimurebasiwepafi.pdf
    • http://fermobkorea.com/userfiles/file/20210907103601.pdf
    • https://weborder.cloud/userfiles/file///wujefevikalipepadujul.pdf
    • http://hairtransplantmangalore.com/uploaded_files/userfiles/files/37556745901.pdf
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/16139e3c02b61e---82708711035.pdf
    • https://diarch.in/WYSIWYGImage/file/mologetevidusumebaduzaxe.pdf
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613d6eb7b83e3---gamirojifis.pdf
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/lpieesb1glrhssvtbee8t8etrd/rerowukukapu.pdf
    • http://huspanda.com/data/ckfinder/files/3405680049.pdf
    • http://wedooverseas.com/userfiles/file/773719760.pdf
    • http://vncdata.net/app/webroot/uploads/files/wesiju.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=how+to+tell+who+looks+at+your+instagram+the+most
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001048b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1048B 16792 bytes
font_01_sfnt_off00011c9d.bin
a0b7742df90e8e347158b9a34c2bb65d454df8edef6a2e2e3e3014f04ce71736
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C9D 18828 bytes
font_02_sfnt_off00014d7b.bin
e92410e230f62bac1c840e92bd1d882d1a0a21c7342a2096fb6e8d1bf0963c99
pdf-font-stream PDF embedded font (sfnt) at offset 0x14D7B 10936 bytes