Malicious PDF — malware analysis report

Static analysis result for SHA-256 491ddb168720258e…

MALICIOUS

PDF

71.0 KB Created: 2021-10-02 16:50:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 66f43caf52df4f1d60479f61d463558d SHA-1: d4d3a37cd1684e08651262a59d1eff8fd9dc53ca SHA-256: 491ddb168720258e56c8c21da25fcf67c2c31c870146bea2a532e96e5363ccaa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were directly extracted, the structure and URL patterns are consistent with a phishing lure designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • 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.
  • 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://careerroots.net/ckfinder/userfiles/files/44793500870.pdf
    • http://dtpokebar.com/uploads/files/rasikibigugakudo.pdf
    • https://mangonebike.com/uploads/file/17698116994.pdf
    • https://eyetracking.pl/userfiles/file/nagomaxasegebewofosoti.pdf
    • http://tensoinox.com/userfiles/files/54177755024.pdf
    • http://teamhead.net/userfiles/file/denok.pdf
    • http://cpgny.com/userfiles/files/meruxid.pdf
    • http://bibliotekaludwin.pl/img/upload/files/kevazadoloj.pdf
    • https://callmarkinvestments.com/callmark/files/35898107382.pdf
    • http://mvsexpo.ru/admin/ckfinder/userfiles/files/2197537792.pdf
    • http://weorderfood.com/uploads/files/razelolulidofuzipab.pdf
    • http://life-homeshop.buyout8.com/asset/uploads/files/tuzuvikatazajowiximelupep.pdf
    • https://gilboamedia.com/userfiles/file/8268968005.pdf
    • http://studiogeologicotrilobite.com/userfiles/files/zudinuzejusezasewebe.pdf
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/161557a2da868d---6962613551.pdf
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/16152231a21e72---fajadakomizilusimel.pdf
    • http://tauroconsulting.pl/userfiles/file/nelupul.pdf
    • https://drakbera.com/ckeditor/ckfinder/userfiles/files/11545018642.pdf
    • http://soeurs-scjboran.fr/soeurs/upload/files/86419218507.pdf
    • http://nexxosrealty.com/userfiles/files/52056415979.pdf
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/13da55d7283adbe5081cf094f9ebb13d/zitolifakimetubawediv.pdf
    • https://dbmotorbrokers.com/userfiles/file/2187576385.pdf
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ecd0db3282---wizimudirog.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=chicago+manual+style+sample
    • 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_off0000b488.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB488 16792 bytes
font_01_sfnt_off0000cc9f.bin
d639267a720923e88f21a6a97347d4203408c0b15f2a1f8d1719b6e582607222
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC9F 10968 bytes
font_02_sfnt_off0000e5fb.bin
6ebb9687087481297f7a964c16e77e86787abce4792022c676cda33b54cb0580
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5FB 15828 bytes