Malicious PDF — malware analysis report

Static analysis result for SHA-256 83ff42c729af835e…

MALICIOUS

PDF

77.7 KB Created: 2021-09-14 14:28:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 8d02436f3f5203cee24e4fdf84676d22 SHA-1: 1499ad316ff81c583ca2d3d709f85bf71cfd1023 SHA-256: 83ff42c729af835e066d826e9cb752dc2f944cd41a5500b6086e8369f964b378
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript, which is a common technique for executing malicious code. The file also features a link farm pointing to compromised websites and disposable hosting, suggesting an attempt to distribute phishing content or malware. The ClamAV detection and ML classifier further confirm its malicious nature, likely as a phishing lure or a downloader for a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 7

  • 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.
  • 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 https://chcial.ru/uplcv?utm_term=reproductor+mp4+android+apk PDF link annotation
    • http://autoscuolapezzano.it/userfiles/files/76826757383.pdfIn PDF document text
    • https://securitydm.com/slicice/file/11608240984.pdfIn PDF document text
    • http://ky-auto.com/uploadfile/files/labepotusiledo.pdfIn PDF document text
    • https://actor-conseil.com/files/file/63988716795.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/161346b312ca56---gorugajikovorobotuliwib.pdfIn PDF document text
    • http://xn--939a66v0zjo3bcvdmrp.com/data/ckfinder/files/20233875851.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/13cb1a7742fb67833f3e4a09a3f19492/76829381308.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab14542723---wuxilura.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161403c4e85119---ratanilogalikad.pdfIn PDF document text
    • http://rymwid-training.com/userfiles/file/mibajowobusidotetevimusik.pdfIn PDF document text
    • https://0286869143.com/editor_images/files/63111987450.pdfIn PDF document text
    • https://mdteam.se/ckfinder/userfiles/files/19394491142.pdfIn PDF document text
    • https://bselink.com/userfiles/file/ladudafaletokanurolos.pdfIn PDF document text
    • https://ngonluathan.vn/images/ckeditor/files/karoxebajagasaf.pdfIn PDF document text
    • https://alcoolassistance-creuse.net/www/site/js/ckfinder/userfiles/files/8540997002.pdfIn PDF document text
    • http://kerekesvillszer.hu/UserFiles/file/wazubutabun.pdfIn PDF document text
    • https://sasalidayanisma.org/uploads/file/dalufazigatiloxuboponi.pdfIn PDF document text
    • http://vipacademy.org/userfiles/file/wowawulemu.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16135ea546561a---suleguparevuragowo.pdfIn PDF document text
    • http://mannadey.in/FCKeditor/file/bumapapamobuwinorobavi.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/ea419b3f2796e3a2c091c211af6663b8/32744442311.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a4c7473d62---lelotarovivutorevowukiz.pdfIn 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_off0000cfc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFC6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e7d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7D8 18188 bytes
SHA-256: 09375442d9e1d48509150c04bcfc8429d9b65504ac05905df04b1183cd51516a
font_02_sfnt_off00011797.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11797 10776 bytes
SHA-256: 077e4865e1c3f8fe090feb883bd7c95415d02d5233243e6d5ee99d5b91526131