Malicious PDF — malware analysis report

Static analysis result for SHA-256 31280e4ae69c013c…

MALICIOUS

PDF

85.0 KB Created: 2021-06-26 16:54:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f56f3e9b216cdc7cb5748ed4a5290273 SHA-1: fe83ebae6df0a75aa4d6dfbf1d8c8f0f09b73ada SHA-256: 31280e4ae69c013c87cc8fb46def201d745490676df96bed29e0afaefb74ca4b
156 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The file contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting it acts as a link farm to redirect users to malicious content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, indicating a tactic to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://catamma.ru/uplcv?utm_term=humorous+person+meaning
    • http://zubrcup.by/files/files/buwiwedomiwiruvob.pdf
    • https://skinrepublic.vn/webroot/img/files/bugaxikojirovapufokuvev.pdf
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1606f32d6a8ee3---22125804922.pdf
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609fa3a6af90b---97884724248.pdf
    • http://myucmas.com/userfiles/file/fapikajoberofigibulax.pdf
    • https://freedomhypnosisnyc.com/wp-content/plugins/super-forms/uploads/php/files/10af4f5fbbe16ce3f3f2b547e22e6632/88813818481.pdf
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/160965211ac76f---20325390975.pdf
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/4497479ac77f346112e19b317ac01de6/44308113317.pdf
    • https://globalmediaminds.com/uploads/files/koleduzoxizajobikifot.pdf
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160aea498d59b3---77956824576.pdf
    • https://infrastone.com/userfiles/files/xokogofunokofikoxuvoki.pdf
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e112cca9d1---daferadad.pdf
    • http://plnjl.com/userfiles/files/rupobubitifenedakodepid.pdf
    • http://samnakthodrahassob.com/userfiles/file/68943122221.pdf
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f751ece55b---7576952616.pdf
    • http://hoangminhphatkorea.com/webroot/img/files/pifepelitaxopewonuto.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608297430df21---durazulufijexevekuponed.pdf
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d90329730---67261300130.pdf
    • http://coreaad.com/DreamDataUpload/file/43000087361.pdf
    • https://vuaship.com/wp-content/plugins/super-forms/uploads/php/files/pejp3p0ktk890sd32tad52hqcb/12283112821.pdf
    • http://woodwork.pl/ubezpiecz/obrazy/file/39211082212.pdf
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16070102c4c27c---24620348862.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_off0000e13a.bin
dc248b76ca619684532fb1b14119a3d12c802eea4e977a3523ea64fffd64fedb
pdf-font-stream PDF embedded font (sfnt) at offset 0xE13A 19952 bytes
font_01_sfnt_off0001150f.bin
e052420162ccbfc5d87f519bd628e4151626b57f16e0d7725097c6556904bda0
pdf-font-stream PDF embedded font (sfnt) at offset 0x1150F 10544 bytes
font_02_sfnt_off00012d04.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12D04 16792 bytes