Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b65f55c7991e99e…

MALICIOUS

PDF

74.3 KB Created: 2021-09-30 21:16:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: a79362e017fcd01d133e79d8741df699 SHA-1: 3773f8fa3a391e24cfc2e717cf27f13a38e83319 SHA-256: 1b65f55c7991e99e77bcf2218e870b495e813f2b9c1e416ae87817f6c82935d0
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, and it contains embedded JavaScript. The PDF also functions as a link farm, pointing to multiple distinct hosts, some of which appear to be compromised WordPress upload directories. This suggests the primary purpose is to redirect users to malicious content, likely phishing pages or malware download sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://chingyi.tw/userfiles/files/85850153712.pdf In PDF document text
    • https://phuketwebstudio.com/ckfinder/userfiles/files/puxezokoguzegipa.pdfIn PDF document text
    • http://feach.ie/images/uploads/file/fivopugujisutip.pdfIn PDF document text
    • http://kaies.net/upfiles/file/fozadinesi.pdfIn PDF document text
    • http://www.pratikchoudhury.com/fckimages/file/21477064452.pdfIn PDF document text
    • http://www.corazondelsol.es/ckfinder/userfiles/files/81726956363.pdfIn PDF document text
    • http://195exim.com/datas/files/mepalaroxe.pdfIn PDF document text
    • https://cissud.it/uploads/ck_editor/files/61090089068.pdfIn PDF document text
    • https://spitalmoldovanoua.ro/ckfinder/userfiles/files/93185562560.pdfIn PDF document text
    • http://carlaschroyen.com/content_docs/julogefoxofizox.pdfIn PDF document text
    • http://krupongs.com/images/file/24196337557.pdfIn PDF document text
    • https://heart-calligraphy.com/uploads/files/202109181845196578.pdfIn PDF document text
    • http://an-ocn.ru/ckfinder/userfiles/files/sidabi.pdfIn PDF document text
    • http://flamefitnessstudio.com/cewit/images/file/tojarodonenavudipiravip.pdfIn PDF document text
    • http://maezawa-jidousha.com/js/upload/files/kisaluriguxoronifon.pdfIn PDF document text
    • https://peintures-descours.fr/fichier/files/narigixafovade.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614772d4aca31---faxalozipeboz.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/tbqcckijpb43ths8qfg2ftd6g2/nuxatanibogamogivup.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210909221706341.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/ff372c547a556da6d4e46d500c1e6a54/gakuwomuxabusekudugaza.pdfIn PDF document text
    • http://laguna.piyawatgroup.com/images/files/rasiluw.pdfIn PDF document text
    • http://abbeytraining.net/userfiles/file/wiveniju.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1614ed3eea8faf---xedazemegewofojolugisuj.pdfIn PDF document text
    • https://barrierball.cl/ckfinder/userfiles/files/91219736366.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=comment+supprimer+une+mise+%C3%A0+jour+androidPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In 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_off0000b878.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB878 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d08a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD08A 18548 bytes
SHA-256: 50943a5c93888ba73d0c9d42f67179bcf12393abc8c0e1e7ed5dc708b43c1780
font_02_sfnt_off0000fff5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFF5 10952 bytes
SHA-256: 2ca36f9ff09bb4613a6e5a89a08a621ae6ef1f8b2190c12837f9d0406c12f20a