Malicious PDF — malware analysis report

Static analysis result for SHA-256 3da658fe3454717f…

MALICIOUS

PDF

82.0 KB Created: 2021-09-05 09:25:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 2dd94f39a873c7f197207f6d1e1ecac8 SHA-1: c4336382ead030c6d1a7bb1466fee339468f6b79 SHA-256: 3da658fe3454717fbff6d6a71e71c7db4c4cde7eddf9a895dabf64a5448e431e
96 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to websites that appear to be compromised CMS uploads, specifically WordPress sites. The ML classifier strongly indicated maliciousness, and the link farm structure suggests an attempt to redirect users to potentially harmful content or for SEO manipulation. No scripts were extracted, but the PDF structure itself is the attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • 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://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/16085e8dcefca3---tazokiw.pdf In PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16083ceffbe79f---83337009357.pdfIn PDF document text
    • http://rakkhunnursinghome.com/user_img/files/mijudogoxalunopizumako.pdfIn PDF document text
    • http://kinel-hunter.ru/upfiles/file/77456215486.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cd00f65e84---44217646686.pdfIn PDF document text
    • https://www.kasekimi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a0f71f378a---duvezonu.pdfIn PDF document text
    • https://thealloywheelcentre.co.uk/wp-content/plugins/super-forms/uploads/php/files/5f2dd77696f2d5e81e52027d5f046514/vinibizuf.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1613352ce726af---619194814.pdfIn PDF document text
    • https://www.hkfew.org.hk/ckfinder/userfiles/files/45878103786.pdfIn PDF document text
    • http://kyanite.tv/userfiles/file/finomivaxoretonatinemile.pdfIn PDF document text
    • http://espacioschillout.es/images/admin/file/vusezupezakejojefexawu.pdfIn PDF document text
    • http://www.deopendeur.org/imgUser/file/30407200416.pdfIn PDF document text
    • http://saltokisport.com/uploads/files/14830315223.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/ea61f86d086a4bed6aeb68697afe3771/gegibivimufegabefozen.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609876ac58299---85537836571.pdfIn PDF document text
    • https://www.pennlighting.com/wp-content/plugins/super-forms/uploads/php/files/0499d0bcf482e92022e7784b635f61a2/31341483336.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16070fcbf20255---vawamolo.pdfIn PDF document text
    • http://china-miyaco.com/img/file/2021773500.pdfIn PDF document text
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/a4a994a606b69d26844a3948a94d1b3f/99209700451.pdfIn PDF document text
    • http://yizhu580.com/ckfinder/userfiles/files/jisokezuzinotazega.pdfIn PDF document text
    • http://agendaalzheimer.org/files/galeria/files/wexan.pdfIn PDF document text
    • http://goldenpeak.it/userfiles/files/77419385769.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=leadership+and+management+assignment+pdfPDF 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_off0000dd25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD25 10736 bytes
SHA-256: f49eb8b1083060baf9d82e0ca73ed9d2fea24a1414ede1fddc9c2aeb6ac0c1a2
font_01_sfnt_off0000f55b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF55B 17584 bytes
SHA-256: e5cb989976418c3069a9876c4aced8cbd5fc0eafc3b7eaeeccb49c7f641e26e6
font_02_sfnt_off00012220.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12220 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1