Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d1a7c5bfc738aa9…

MALICIOUS

PDF

72.0 KB Created: 2021-09-28 07:28:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: c7776b23e04dc771f7e276a7fa697bf1 SHA-1: 1d98d8f50f123228b2dd0509913c9536924fc1d7 SHA-256: 4d1a7c5bfc738aa906630fa910df3fec45740d9fe85f7c84017f337fc70a56ac
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 CMS upload storage or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

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://synerhu.ru/uplcv?utm_term=crazy+stupid+love+online+free PDF link annotation
    • http://nasfthr.com/userfiles/file/55238869849.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/eatpksg5ef1agl03jgom9fet3n/zazanamurafetis.pdfIn PDF document text
    • http://nakamurasangyou.jp/app/webroot/uploads/files/59782320285.pdfIn PDF document text
    • http://wonsakai.com/uploads/files/bugipufuwanex.pdfIn PDF document text
    • https://mytopics.it/uploads/file/tuxidutabegakegowakebi.pdfIn PDF document text
    • http://davidhammerstein.org/userfiles/file/tajakiwesovowaki.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/16144bdaa4dcce---mikowafetapube.pdfIn PDF document text
    • http://mhinflatable.com/upload/file/muvibuvipavobes.pdfIn PDF document text
    • http://clear-es.net/yamituki-n/uploads/files/1828787386.pdfIn PDF document text
    • http://www.erealitysolutions.com/tennisontario/assets/appsadmin/js/ckfinder/userfiles/files/sunolulesarezop.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/ad220108dae67dce9c5c7ecf88c7a9bf/52833356430.pdfIn PDF document text
    • https://plasterglasgow.com/fwd_docs/file/gopukoluj.pdfIn PDF document text
    • https://abctranslink.com/ckfinder/userfiles/files/kofomafijow.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/44105060606.pdfIn PDF document text
    • http://www.travelwithtaangoo.com/img/file/62675013902.pdfIn PDF document text
    • http://pickup-ws.com/userfiles/files/kefeporezenuwi.pdfIn PDF document text
    • http://electronicaindex.nl/images/uploads/83172349263.pdfIn PDF document text
    • http://thai-apsproducts.com/file_media/file_image/file/84089315679.pdfIn PDF document text
    • https://didacostruzioni.it/userfiles/file/50340020780.pdfIn PDF document text
    • http://www.tomasjelinek.com/img/pub/file/merituxuso.pdfIn PDF document text
    • http://ambvetsanprospero.eu/userfiles/files/8125907591.pdfIn PDF document text
    • http://togul.org/sites/default/files/file/96511966973.pdfIn PDF document text
    • http://levne-pohary.cz/UserFiles/File/30056608637.pdfIn PDF document text
    • http://abwpetersburg.com/uploads/files/93690887735.pdfIn PDF document text
    • http://autowassenindex.nl/images/uploads/23439638490.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614bb5b7ae225---61401875939.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ec2e54c2b3---1684637459.pdfIn PDF document text
    • 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_off0000b491.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB491 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cca8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCA8 10860 bytes
SHA-256: ba9245c096c98ddc78152b1f4df410c55e4a1ec6da3f38a4ca2b073226e3b690
font_02_sfnt_off0000e5f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5F9 17112 bytes
SHA-256: d86a86edd998e204a05621734d43764a35a1493941098dabede20889b70e401e