Malicious PDF — malware analysis report

Static analysis result for SHA-256 b18a3b10755c76f9…

MALICIOUS

PDF

80.1 KB Created: 2021-09-19 23:09:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d98d830aa9c5b64543ec433e24103172 SHA-1: 48ac06e9798b908fea260fde06ffd29be6e66193 SHA-256: b18a3b10755c76f9481a335351b32b25353c56f7ee383433ae6503b657d9bb2c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a link farm structure, suggesting the document's primary purpose is to redirect users to potentially malicious or phishing sites. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://infrive.ru/uplcv?utm_term=best+oil+painting+app+for+android
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/d1604243319c30da6063ecf48d8c024d/64009843201.pdf
    • http://footstepfloor.com/upfiles/files/12105017898.pdf
    • http://sten.kr/club/data/userfiles/file/20210902075030.pdf
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/161457899ad1e8---73951860996.pdf
    • https://ahl2005.com/ckfinder/userfiles/files/56944707256.pdf
    • http://mnwebdesign.dk/userfiles/file/bekajoronetiron.pdf
    • http://cetis156.neutronds.com/assets/js/ckfinder/userfiles/files/bivunomukavuputoxolasom.pdf
    • http://capthepcongtrinh.com/uploads/news/files/41179797012.pdf
    • http://rockhousemethod.com/ckfinder/userfiles/files/popokuwap.pdf
    • http://quangcaosms.org/media/ftp/file/dofirelijo.pdf
    • http://jacsonsfurniture.com/userfiles/file/60629580936.pdf
    • http://aytekinpolatel.com/image/files/gugedibubobexewebori.pdf
    • http://parzenica-bialka.pl/userfiles/files/xilafijigumexim.pdf
    • http://www.andreapondika.cz/file/99231921418.pdf
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/161415cb9a432d---44499143465.pdf
    • http://roberlo.cz/www/files/file/33303099306.pdf
    • http://bancasemecanino.com/userfiles/files/2018590465.pdf
    • https://ibericadearmerias.com/file/darebagitanulitejagesuvaz.pdf
    • http://medica-brno.com/files/3249335136.pdf
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/2v1ngrtef84rp4ao6cu5hts4o0/89855160583.pdf
    • http://carneslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/27636797821.pdf
    • http://ziguratex.com/helpdesk/app/webroot/img/userfiles/files/nokotiwopepobibemegiw.pdf
    • http://sinoorchids.com/image/file/kurakofazulapit.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_off0000d6dc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD6DC 16792 bytes
font_01_sfnt_off0000eeee.bin
81d18d410f59723c7dc6c0bf0550658330dfb48326db281474b2a3f0db169abf
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEEE 16504 bytes
font_02_sfnt_off000119c0.bin
ee4f7b1afb52dae1b3bb908265aa554912ea718cf935d50d59dd98ff2a9c734d
pdf-font-stream PDF embedded font (sfnt) at offset 0x119C0 10728 bytes