Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb44dc81c65b16c9…

MALICIOUS

PDF

93.5 KB Created: 2021-07-22 04:06:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5f273d762f9aad1dbf120b2243ccd434 SHA-1: 68fb44176f7621a80eacb3ae5df5882fcc53db22 SHA-256: cb44dc81c65b16c9d1be3f7e52d6649159e1098940b2b2ebff30b5e016d03041
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting, likely to redirect users to malicious content or exploit kits. The presence of external URIs and link farm heuristics strongly suggests an attempt to lure users to external, potentially harmful, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://asja-doll.ru/userfiles/file/kolubebuloda.pdf
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/7390de4b4353d3b4aa3167f11064d1b9/73092973799.pdf
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a73ae379301---faxanir.pdf
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a03c42b1dee---xerikenuwovo.pdf
    • http://keystoparadise.com/userfiles/files/76418324632.pdf
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160cc8a6b91c4c---3612316363.pdf
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d50b8f74c16---duxef.pdf
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/b5a316161e94ce9c59f22b4f83472d3e/fixevupaf.pdf
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071eb46c8647---12540772778.pdf
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/9bbde2e382b7892c1d9f925391608cc6/xatenepeminemaxomiw.pdf
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a132ec2ab9b---79132400860.pdf
    • http://boschvietnam.vn/files/usersfiles/files/79707109576.pdf
    • http://topas.lt/userfiles/file/23676316245.pdf
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160808c6177fda---zinobeke.pdf
    • http://gillsandgeckos.com/userfiles/file/5735144135.pdf
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/b86bcb15848060d109f79f16c63c9cd6/nodafibovo.pdf
    • http://tamilannuaire.com/var/www/vhosts/vps296430.ovh.net/tamilannuaire.com/images/file/wojojemefebujabuvunakawus.pdf
    • https://qualitymattressfactory.com/admin/userfiles/file/bufijefaxugesavino.pdf
    • https://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/458821fd0d6ce54f1b3cf5d0f023558b/21364803334.pdf
    • https://ngoctraithaibinhduong.com/uploads/news_file/11203238705.pdf
    • https://sankaibearing.com/userfiles/files/rukaxujijawisew.pdf
    • https://clic-essc.ch/ck/ckfinder/userfiles/files/nivovenikijox.pdf
    • https://vettercycles.ch/userfiles/files/jakusenupekerilujug.pdf
    • https://onhimalayas.com/ckfinder/userfiles/files/7331584490.pdf
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3aafe0ab7---xobejaja.pdf
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c43877d4d81---70391375522.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=name+of+steroid+shot+for+allergies
    • 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_off000107ac.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x107AC 16792 bytes
font_01_sfnt_off00011fbe.bin
31532cbdb8bc89a02bb143b98e58de5058e353fbe4ea448a35b449691236be4a
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FBE 18720 bytes
font_02_sfnt_off00014f91.bin
9126faba2ce66daae432f5fa3deb83607454cdb8df084a51032f118efc205c58
pdf-font-stream PDF embedded font (sfnt) at offset 0x14F91 10676 bytes