Malicious PDF — malware analysis report

Static analysis result for SHA-256 f833cd180e16f91c…

MALICIOUS

PDF

87.5 KB Created: 2021-09-17 22:36:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: b496cb40ba614e457fdfe99aa3312dd0 SHA-1: a13089f240a001536bd61658e4fb02dce371be54 SHA-256: f833cd180e16f91c17d508f24718fc0642c2c34ee359b5b84be2c35049c408f5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs pointing to various domains, many of which appear to be disposable hosting or compromised CMS upload locations, indicative of a link farm designed for phishing or malware distribution. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://medvor.ru/uplcv?utm_term=gandr+collage+maker PDF link annotation
    • http://baheth24cars.com/ckfinder/userfiles/files/bujituvefud.pdfIn PDF document text
    • http://aumnat2car.com/ckfinder/core/connector/php/upload/files/begufa.pdfIn PDF document text
    • http://szintai.hu/ckfinder/userfiles/files/momikanerotasowumulemava.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/3812fa51b2d30d7a38aedf0c145dd57f/19012939753.pdfIn PDF document text
    • https://www.mppoa.cloudlinesystems.com/assets/ckfinder/userfiles/files/digesin.pdfIn PDF document text
    • http://meruzhankhachatryan.com/app/webroot/files/file/2860347233.pdfIn PDF document text
    • http://miroslaws.com/ckfinder/userfiles/files/suvevaxelun.pdfIn PDF document text
    • http://millecolori.it/images/file/3649757587.pdfIn PDF document text
    • http://finance-bulldog.cz/UserFiles/File/9945298043.pdfIn PDF document text
    • http://articolo17.it/siti/usr/foto/files/gotadaxufotepujebumobiw.pdfIn PDF document text
    • http://cyuanmei.com/userfiles/file/kuwise.pdfIn PDF document text
    • http://twsl.mingann.info/upload/ckfinder_temp/files/20210915093242.pdfIn PDF document text
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/aj59ktji9hfp2at16hg1nsadkv/88407641872.pdfIn PDF document text
    • http://gardatrans.com/content/Files/kevisumigetum.pdfIn PDF document text
    • http://sungder.com/upload/44204421343.pdfIn PDF document text
    • http://hkbroadwin.com/userfiles/ladavituxifav.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/jidurijaxubafitasetakava.pdfIn PDF document text
    • http://ssanadia.in/userfiles/file/bexifalebuvaxixen.pdfIn PDF document text
    • http://dagmare.de/userfiles/file/86163411927.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/16141fc15bfffc---15728423656.pdfIn PDF document text
    • http://infas.cz/images/wiswig/file/61201412709.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/pisilujifusis.pdfIn PDF document text
    • https://lifesmart.lifesmart.ro/ckfinder/userfiles/files/taraworikidewofen.pdfIn PDF document text
    • http://fleshlight-tw.com/userfiles/file/47009666598.pdfIn PDF document text
    • https://dodomacnosti.net/data/file/pixawazafogove.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_off0000efab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFAB 10488 bytes
SHA-256: 500ab41d7923a7a302dff0c0c6d156c2a4e9baa53f33b4c04bc7483ccb446218
font_01_sfnt_off00010746.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10746 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F58 18732 bytes
SHA-256: 57ee376eb2418ec58f51d606242acb36f9c28c9863a8fea0232b3959c2363181