Malicious PDF — malware analysis report

Static analysis result for SHA-256 ea57a3ef164c485b…

MALICIOUS

PDF

81.3 KB Created: 2021-09-02 10:13:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 49cf632975bb1ce61ff91f3fc71fecf7 SHA-1: dea43336cdff3e5f058dbeed20a9b9ef92333d31 SHA-256: ea57a3ef164c485bbd3ef77ece31d7b559b8a5d132521f9ba9fbab1ee7245aef
96 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites and other disposable hosting domains, indicating a link farm or SEO poisoning attempt. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple external URIs supports a malicious intent to redirect users. No scripts were extracted, but the structure suggests a lure to potentially download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://anapro.com/ckfinder/userfiles/files/87812195735.pdf In PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082ab4e63372---99719384264.pdfIn PDF document text
    • https://sealordhotels.com/ckfinder/userfiles/files/ruzisubexetatesidow.pdfIn PDF document text
    • https://kitapkaplama.com/upload/ckfinder/files/88906545334.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/nufixagawibul.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/202ae15178167b9bdbf067b35971ffaf/gazuj.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbcd6ad6377---25744578473.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b34b80e85a---82577921309.pdfIn PDF document text
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/cr08inkmgo6t2frqvcsj5kmp0b/dolemagov.pdfIn PDF document text
    • http://george-dollie-nelson-mass-reunion.com/clients/3/33/33de80a6744892f7217a81a137582dad/File/pewotarol.pdfIn PDF document text
    • http://chothuexehochiminh.com/userfiles/file/bakafum.pdfIn PDF document text
    • https://dcimx.com/files/37598514128.pdfIn PDF document text
    • http://networkinglikepro.com/ckfinder/userfiles/files/90232751723.pdfIn PDF document text
    • http://chi-kara.net/userfiles/file/71599229027.pdfIn PDF document text
    • http://benly-carson.com/product/files/sigejoxegov.pdfIn PDF document text
    • http://blankheich.de/images/uploads/file/kojonivufakab.pdfIn PDF document text
    • https://noddy.nu/images/file/84506895143.pdfIn PDF document text
    • http://canxetaidientu.com/images/file/2322031071.pdfIn PDF document text
    • https://uslugiinzynierskie.com/eurostyl/photos/file/38623846651.pdfIn PDF document text
    • http://manuale.aziendasulweb.it/userfiles/files/95164693877.pdfIn PDF document text
    • http://hpworld.hu/data/pic/Image/file/7435246415.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=binomial+to+normal+distributionPDF 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_off0000d6a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6A0 18548 bytes
SHA-256: c8b8918de4f025995d6edcb1a032fd6a1850f8fd49d5c556f5dc6a1461a10c1b
font_01_sfnt_off00010789.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10789 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011fa0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FA0 10568 bytes
SHA-256: 50a3758f12825ee9c2eb2ecaec964abe8c2eaad99216e975cd4bde6a3e7e9d45