Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b8bfe71509d6f51…

MALICIOUS

PDF

71.4 KB Created: 2021-09-12 02:04:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 442884e190667e3105a8aec40e9bc35c SHA-1: 73b8e1c1e20f921ad3ade7c08fcb9458c730f92c SHA-256: 6b8bfe71509d6f51941ac14a8ac7a83a5a77fc2d3b48dda3fed84d92a9e618fc
164 Risk Score

Malware Insights

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

The sample contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. The PDF also features a link farm pointing to multiple PDF files hosted on compromised WordPress sites, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613b83f35dff2---soropu.pdf In PDF document text
    • http://digifast.cz/userfiles/7088095019.pdfIn PDF document text
    • https://nsstore.mx/ckeditor/ckfinder/archivossubidos/files/junafunegarevive.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/9mauqfvn5qllfu9hnimipsbr67/37142634894.pdfIn PDF document text
    • https://renfrewareahealthvillage.ca/ckfinder/userfiles/files/58693020913.pdfIn PDF document text
    • http://www.beverburcht.nl/upload/files/56719904368.pdfIn PDF document text
    • https://patc.fr/imagesfile/49323379669.pdfIn PDF document text
    • http://dyglas.com/userData/board/file/29961185728.pdfIn PDF document text
    • http://daotaonhaccong.com/uploads/userfiles/file/50061818697.pdfIn PDF document text
    • https://yodishit.com/uploads/userfiles/file/fimotolaxebunamogubazi.pdfIn PDF document text
    • http://m-styleauto.com/js/upload/files/73727795653.pdfIn PDF document text
    • https://ww150005.linebot.net/upfile/files/20210902213722.pdfIn PDF document text
    • https://thisissati.com/userfiles/files/82446096898.pdfIn PDF document text
    • https://iamtimeshare.com/userfiles/file/gugeputixiforiji.pdfIn PDF document text
    • http://sahcarpets.com/userfiles/file/vezat.pdfIn PDF document text
    • http://tearose-kitchen.com/sites/default/files/images/imcefile/gilagiladij.pdfIn PDF document text
    • https://vmgeducationtrust.org/home/vmgedu/public_html/public/userfiles/file/musibubegifa.pdfIn PDF document text
    • http://belloverde.net/emailer/file/35173380715.pdfIn PDF document text
    • https://www.milestonesmn.org/ckfinder/userfiles/files/96374494964.pdfIn PDF document text
    • http://speed-r.com/js/upload/files/febaretovamebatubekeb.pdfIn PDF document text
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/cfdf5ed4a0036e5669151001c148dbc2/mesojalinajodurarozinuv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=a+quite+place+downloadPDF 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_off0000b5f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE03 16272 bytes
SHA-256: e64c2d4b3c3f36ce6d78ac4eb8974c12b3964d7eb17e8be070c3a2a6dea46a4b
font_02_sfnt_off0000f812.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF812 10552 bytes
SHA-256: 27f62af162158c0b27b0e4f058220a08ffd2ec9bf4e9db4a42eaeeba99efe540