Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6839274e946bf0e…

MALICIOUS

PDF

81.2 KB Created: 2021-10-09 22:43:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 4616f7cb0100f6e5838fe40117e632c5 SHA-1: 6948c8a6cd5e6b0dbd1f71b3f05960d4b1ae1d54 SHA-256: a6839274e946bf0ec989489a751cfa9bf72bdabe8a3fc59f4de5cd1404b059f7
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many pointing to compromised CMS upload directories, suggesting it functions as a link farm designed to redirect users to malicious sites. The presence of these links and the overall structure strongly indicate an attempt to distribute malware or conduct phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://drafthe.ru/uplcv?utm_term=outstream+video+ads+example PDF link annotation
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161527d03d1e4b---73828872807.pdfIn PDF document text
    • https://altsovmun.ru/userfiles/file/11292126759.pdfIn PDF document text
    • http://csa.china-led.net/static/editor/ckeditor/ckfinder/upfile/files/vurakobuduluxukeditafa.pdfIn PDF document text
    • http://ooexperience.be/assets/Image/files/67455313614.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/23743615322.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16154261167259---61894300053.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16158a05f2beca---narepufixozol.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148d9c95168f---44248573123.pdfIn PDF document text
    • http://agroanaliz.by/upload/editor/files/35537990259.pdfIn PDF document text
    • https://eletroluz-al.com/_IMG/img_internas/file/surimevapowujulizuw.pdfIn PDF document text
    • http://yushendesign.com/images_fck/file/1631201113.pdfIn PDF document text
    • http://distant-property.ru/fck_editor_files/files/7080098991.pdfIn PDF document text
    • http://contua.org/userfiles/file/burarovujiguzaje.pdfIn PDF document text
    • https://unitjaya.com/contents/files/38451591778.pdfIn PDF document text
    • http://gocchame.vn/app/webroot/img/uploads/files/jefonitenijuzisovixiwoziv.pdfIn PDF document text
    • http://bilcafe.it/userfiles/file/kuvonanen.pdfIn PDF document text
    • https://fluffy-chins.com/images/file/sopefizebizewiwa.pdfIn PDF document text
    • https://www.ccs-corporation.com/ckfinder/userfiles/files/36265157679.pdfIn PDF document text
    • http://traiteur-ribot.fr/userfiles/file/87644990517.pdfIn PDF document text
    • http://naszymsladem.pl/upload/file/fumuxebapina.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/67802216324.pdfIn PDF document text
    • https://vsetinrally.cz/userfiles/file/55506829481.pdfIn PDF document text
    • https://manninghamhouse.com/userfiles/file/3508050788.pdfIn PDF document text
    • https://www.hippocratio.gr/ckfinder/userfiles/files/90984169433.pdfIn PDF document text
    • 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_off0000d4da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ecec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECEC 19048 bytes
SHA-256: aa789543847d8d0604ac793c111f20345316e72b16392a9cd56f3bc2f1c7de58
font_02_sfnt_off00011df1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DF1 10740 bytes
SHA-256: 4cca5f3d378c5f7aa9f94547b8a51b13d60cda8028bd74386d407128f2dcb492