Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8cd8a71bab75715…

MALICIOUS

PDF

85.9 KB Created: 2021-07-10 06:21:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 742ca909586cab1b3bcfc067b65ed43c SHA-1: 6e3e6aad75a1c3d4b2c008f2966fdbcd8cc28f8c SHA-256: f8cd8a71bab757154b4022f76569ed37ba7e4df1b02b4c430577d97e04c5bc4a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document detected as malicious by ClamAV and an ML classifier. It contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users. The presence of external URIs and the nature of the links indicate an attempt to lead users to malicious content, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://coretry.ru/uplcv?utm_term=the+loch+ness+lake
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/6948d2fcabd2054d5dbba0aae1afd99d/logotefoxuvenu.pdf
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a73b3e9ff24---71726499987.pdf
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16097232fd0f42---vokajiwulazezamuzuvoxigo.pdf
    • https://tedvandergulik.nl/userimages/file/76267620050.pdf
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/160c5133866688---nobovuj.pdf
    • https://www.passion-rnd.com/upfile/files/2021/06/13/tifoweba.pdf
    • https://casabresciani.it/uploads/file/73814117180.pdf
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/160812a201dc96---rugomabanigop.pdf
    • https://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/9d6856d8dbf36295cd9842f02dab49e1/9197023176.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/rovpnpvrni5g6du5gpknd1ngg8/4149713383.pdf
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/9v1lsevi2bqft1c4t6nrloj9sq/wajijomavagunozazunidafes.pdf
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160c780f6afb78---63342282954.pdf
    • http://kristenpell.com/userfiles/files/vexukevemosasena.pdf
    • http://pune-india.info/userfiles/file/70973513816.pdf
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3433919736---kofejogefebefimitoju.pdf
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160a25135e6681---59514587156.pdf
    • http://apexhealthnutrition.com/newerac2c/userfiles/file/90877717993.pdf
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/uvuv51baaoicd8acsp938rq4vv/zajujipomonesanos.pdf
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/9a2f8e3ca57e8f1f8f44c84f0aa0b1b3/perepujubijiregi.pdf
    • http://dreamcatcherltd.com/userfiles/file/51759887518.pdf
    • http://maynenkhipuma.vn/quangbasanpham/app/webroot/upload/image/files/71517317273.pdf
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608433c5eccef---xosokebiziduxufiweti.pdf
    • https://vildmarksjagt.dk/userfiles/file/85621867560.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_off0000ee3d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE3D 16792 bytes
font_01_sfnt_off00010654.bin
5e20fad9e6b6996a6ee3f921d59f3abc990829a81a299f1117d7e2f9031be8d1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10654 10092 bytes
font_02_sfnt_off00011ccf.bin
088d6730a297030badfadaed5520b55630bc2d5fbeff4a627945ed94639c22d0
pdf-font-stream PDF embedded font (sfnt) at offset 0x11CCF 17672 bytes