Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b706da4d8a1ccd6…

MALICIOUS

PDF

70.7 KB Created: 2021-09-24 21:23:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 516c8a0e94bf3190b5ea85ad4a3f2502 SHA-1: 763ac26cfa7a7566f770e4d30fe831f1b0ed2911 SHA-256: 4b706da4d8a1ccd63245c5bb272d6127ed7a35cef731ee9e162b495a04e3a6b7
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations, indicating a link farm or redirection strategy. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The presence of multiple compromised CMS upload links and the overall structure point towards an attempt to obscure the true destination or host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16134d842b274d---numezizuf.pdf In PDF document text
    • http://lixupeng.com/uploads/files/44592814221.pdfIn PDF document text
    • https://exam10.menapoint.com/app/webroot/upload/files/63895109317.pdfIn PDF document text
    • https://kalimati.in/userfiles/file/34862172275.pdfIn PDF document text
    • https://rowsontw.com/shopadmin/upload/files/jisarivikiremusaket.pdfIn PDF document text
    • https://ecoquimica.cl/dinamicos/uploads/file/sezudefulodenizotutes.pdfIn PDF document text
    • http://designerhouse.ru/upload/files/sofakizamu.pdfIn PDF document text
    • http://paraleumarian.ro/app/webroot/files/userfiles/files/20821691995.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/h4vonmc6a926fvi2d9bt3jt1rm/15122396612.pdfIn PDF document text
    • http://jumpinfit.it/userfiles/files/derinekelozo.pdfIn PDF document text
    • http://blessingsngo.in/userfiles/files/21777571847.pdfIn PDF document text
    • https://fresh-cherries.com/ckfinder/userfiles/files/babopazarexabituz.pdfIn PDF document text
    • https://maymac.info/userfiles/file/3954689164.pdfIn PDF document text
    • http://okmarin.ru/userfiles/file/kilepupimaxasekade.pdfIn PDF document text
    • https://sport-jicin.cz/dokumenty/26152387433.pdfIn PDF document text
    • http://gzwep.com/img/file/20219114119.pdfIn PDF document text
    • http://studiofapas.it/userfiles/files/87507657067.pdfIn PDF document text
    • http://arcstema.com/userfiles/files/89269117755.pdfIn PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/bi05iemqnh805rorak7t3jnpf0/98052759638.pdfIn PDF document text
    • http://belean.pl/userfiles/file/22708768553.pdfIn PDF document text
    • http://thesciencenetwork.org/uploads/files/71395487285.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=root+nexus+10PDF 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_off0000b07e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB07E 18500 bytes
SHA-256: 8e6e8ba42f958c2e779718faf6e011c5c6dc99f595ae1d6bda34eb25cec8f6ba
font_01_sfnt_off0000e006.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE006 10124 bytes
SHA-256: 4801a9db4bccbd9caadc979899a3305e927de96517bcd1ebd9fed167edb40a3e
font_02_sfnt_off0000f6e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6E2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1