Malicious PDF — malware analysis report

Static analysis result for SHA-256 81e8c489fbc70d8f…

MALICIOUS

PDF

94.1 KB Created: 2021-07-04 02:47:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b38d24b5686da31f512e941dd1ef1430 SHA-1: 2b4e4b4071b3c6d41c5b3bab60f9abb76e1d41d0 SHA-256: 81e8c489fbc70d8f9fc62173acd02d6becdd43b23f9684b3a34a56eb42ec9788
164 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous links pointing to compromised WordPress sites, indicating an attempt to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of a link farm on disposable hosting further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

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://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a55f99841dd---selukoj.pdf
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b0bfc2a301---13868713325.pdf
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e0e64e0fe1e---60872341732.pdf
    • https://carstenrath.com/wp-content/plugins/super-forms/uploads/php/files/68o7f1q683m16i1kn3e7ae4n66/56927774293.pdf
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608c8c8830d4f---7305975236.pdf
    • http://brandnewgoods.net/userfiles/file/15701161557.pdf
    • https://fullhousetourism.com/UploadFiles/file/20210525025247135.pdf
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/l90hnt2r4tp7gckcq3qqt73jmg/genubi.pdf
    • https://grafitpoint.ru/wp-content/plugins/super-forms/uploads/php/files/4a5cf595c9fc14e01b25d9271e2aaeff/69450207569.pdf
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/358245bf195795da667b4635be5d4042/dubuluwola.pdf
    • http://studiosimonepantaleo.it/userfiles/files/manofuxupaxiwatebiwo.pdf
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/e8f7a2beaa55f2f8038ef7150d22fc20/3835600103.pdf
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/e204a26c26bffe7763426268a86af022/tamebapimixowumav.pdf
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160a91fa480ec0---58268837200.pdf
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/1653c4691233c770daa5a545fa34bc09/wenutovipiwa.pdf
    • http://sacoorhealth.pt/site/upload/file/sasesado.pdf
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606eabb6a736f---vinalorasod.pdf
    • https://imad0c0.com/js/ckfinder/userfiles/files/51506415304.pdf
    • https://triptoboloyfoundation.org/editorsfiles/files/donuwen.pdf
    • https://ural-aiti.ru/admin/ckfinder/userfiles/files/11808244183.pdf
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/ceqmd6q8l9onu3pmqop0rm8bc8/tilegowovuposotab.pdf
    • https://alshuka.ps/ckfinder/userfiles/files/24152903557.pdf
    • https://x-software.cz/data/file/sakiniguromago.pdf
    • http://occahomesearch.com/userfiles/files/67638023553.pdf
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160839038269f8---wijetemijixod.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=examples+of+antiretroviral+drugs
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010c18.bin
c9487dac408d44db31acaf2f3f8aec14faf0b791282f1ecff737ee2952aec814
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C18 17212 bytes
font_01_sfnt_off0001392e.bin
9811feaf68dda5b9219fde4471e6e9011de8a4d69937a4862449c08312c3e1d6
pdf-font-stream PDF embedded font (sfnt) at offset 0x1392E 11092 bytes
font_02_sfnt_off000152dc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x152DC 16792 bytes