Malicious PDF — malware analysis report

Static analysis result for SHA-256 c23b19c5d51c2711…

MALICIOUS

PDF

88.1 KB Created: 2021-07-05 04:12:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3f94d06d288c410f10ce78539348d3ca SHA-1: cf05308d612832a76978856b56141d89915f7f62 SHA-256: c23b19c5d51c27117a3265d4f21366ab217f1cdb5bd5bdad73997ad2adda9025
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF that contains numerous links to external websites, many of which are hosted on compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests a tactic to obscure the true destination by using disposable hosting and link farms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://irlanc.ru/uplcv?utm_term=hiccups+after+chemo
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/551b75b1f2fbc750b0e0e0e4a2ec769c/liditusotelonatu.pdf
    • http://cn-polylysine.com/d/files/tepupu.pdf
    • https://10glazsikeyrosa.ru/file/20275740673.pdf
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/98d4ecbbb782cb6b0f2dd2dbe13d2c93/zeletojivow.pdf
    • http://alexhoffordphotography.com/temp/files/file/sakilus.pdf
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/d7a7a18b0ffd78ce6d566231703cdf8d/xizovetawa.pdf
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/18c54e174dfa23cee4dcc983430ccd2b/luguwogubefa.pdf
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/bac2e4380637b1f18d27f4d938c2a731/82743261598.pdf
    • http://dollreunion2020.com/clients/4/43/4392dc7a9e9236654a628da0af121bbb/File/81214807436.pdf
    • https://aawyx.com/sites/default/imageuser/file/60858198117.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/paqsvt4e69ofac56utt20ulou6/kopunugajusuvudukube.pdf
    • http://dirabrealtors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abf861b58f9---92139434310.pdf
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ad99e0ddc2d---19190473826.pdf
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/160a7d6acc4f25---3139102860.pdf
    • https://kawanmto.net/contents//files/vumajoko.pdf
    • https://abofahed.com/userfiles/file/72199998943.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606c93aa88e44---jobipuwemoge.pdf
    • http://orourkelawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jemipitorepoze.pdf
    • http://ksnjl.com/userfiles/files/mofuzexaju.pdf
    • http://itnetworkconsultingsf.com/helpdesk/app/webroot/img/userfiles/files/kitoramoj.pdf
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/160aa6078bcf61---suvalavewevixelaruta.pdf
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b420d442abe---33642932592.pdf
    • http://opalsolar.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607332af7c9f4---kesajozovofonem.pdf
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/160e121e4ab719---nevimitur.pdf
    • 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_off0000f6ec.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6EC 16792 bytes
font_01_sfnt_off00010efe.bin
a54f595b106532dc76c182383d1513e4247bad5213a4579d97cedf42a729daa0
pdf-font-stream PDF embedded font (sfnt) at offset 0x10EFE 16940 bytes
font_02_sfnt_off00013afc.bin
5be1fccbcd9f76e5c3dd8e506f15aab9c531ba3e1d5e8c430a5221a58bc0cec1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13AFC 10688 bytes