Malicious PDF — malware analysis report

Static analysis result for SHA-256 ed538e655b8bc231…

MALICIOUS

PDF

83.1 KB Created: 2021-09-20 15:33:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 8dc5dad0cb19787222b9326aebc14fa7 SHA-1: 23b19ff88e42fde8f3214458d8b8d8fe5cee6b1e SHA-256: ed538e655b8bc2318ed5d45c3a6bf1e0ae70bff402b6747fa12443bbca9545d6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a PDF link farm, with numerous URLs pointing to disposable hosting and compromised CMS uploads, suggesting a phishing or malware distribution scheme. The embedded URLs and the nature of the link farm point towards an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • 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.
  • 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://oniceh.ru/uplcv?utm_term=video+studio+app+for+android PDF link annotation
    • http://rubivina.com/Images_upload/files/janulexalugiruvaterigonim.pdfIn PDF document text
    • http://movesearchesuk.com/userfiles/file/vikivasupe.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/dogepegawu.pdfIn PDF document text
    • http://soles2walk.cz/data/file/pitizamunapatog.pdfIn PDF document text
    • http://phutungquanghieu.com/app/webroot/files/ckfinder/files/28184341241.pdfIn PDF document text
    • http://china-miyaco.com/img/file/20219310565.pdfIn PDF document text
    • http://ingmarcofaedi.com/userfiles/files/16703655036.pdfIn PDF document text
    • http://cluboutletmoto.net/campannas/file/80286664484.pdfIn PDF document text
    • http://okzawidow.pl/img/upload/files/filot.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/667c78fe00d3b5cde43f5436c6e2bdcd/42667156259.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/h9jl06ea4bf0h2eb8kpp0jkvr5/lawigosewerokigavinune.pdfIn PDF document text
    • http://akinmedikal.com/uploads/file/buredujan.pdfIn PDF document text
    • http://www.libroparlatolions.it/backoffice/ckfinder/userfiles/files/97308347305.pdfIn PDF document text
    • https://servicepapik.ro/files/39411799828.pdfIn PDF document text
    • http://moje-stranky.eu/userfiles/file/madaguvegexa.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613440dee6e9c---wotozo.pdfIn PDF document text
    • http://allasclub.com/campannas/file/zukomofik.pdfIn PDF document text
    • https://guapa2.com/admin/fck/file/4555111840.pdfIn PDF document text
    • https://petrovsky14.ru/docs/files/jekutezawimaxu.pdfIn PDF document text
    • http://budropol.de/Upload/file/vafenizosumitupax.pdfIn PDF document text
    • http://cariboohose.com/userfiles/file/zalilagogujexadodi.pdfIn PDF document text
    • http://another-partner.morefriendship.com/upload/files/zuxirelofalazizi.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea4a76ae1b---renagilokowinorujipob.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_off0000e2cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2CC 16732 bytes
SHA-256: 5e078f2256c9d5dca8eafd6dbabb049b06fe6896c49d5e410acd7da80d198143
font_01_sfnt_off00010e2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E2F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012646.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12646 10512 bytes
SHA-256: f1250f631ae6cdaae7ad974e3ffc92602402df7007d725b7ec9a21897b329ef1