Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff92d6a875144508…

MALICIOUS

PDF

92.0 KB Created: 2021-09-10 10:04:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 83c9bcd892b41f17621c493dfa9ec2b2 SHA-1: e53667ce355a5b9a0ec50f45ccf44c9ec0a9bdc2 SHA-256: ff92d6a875144508a0656a221affe80ab4f156505b8a24cf6b145da492ccfd44
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a link farm with numerous URLs pointing to other PDF documents hosted on various domains. Several heuristics indicate that these links are intended to be a link farm, potentially for SEO manipulation or to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

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 http://sjatupornservices.com/file_media/file_image/file/99765536361.pdf In PDF document text
    • http://bubb.cn/up_file/file/pupuvubenigifikajeguwi.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133fd94e463b---pokorefirubar.pdfIn PDF document text
    • http://kfoodntea.com/dataroom/file/zovuvakosufebo.pdfIn PDF document text
    • https://justforjetscatering.com/userfiles/image/files/89320980712.pdfIn PDF document text
    • https://ismart99.net/upload/files/45170351493.pdfIn PDF document text
    • http://hoangduy.vn/vn/files/wikatorowixapatorev.pdfIn PDF document text
    • http://bbfederico2.net/userfiles/file/sutudi.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/6009v9r1e4de54b52c3f5nqo68/73603682260.pdfIn PDF document text
    • http://eastwoodfamily.net/userimages/sipobek.pdfIn PDF document text
    • http://ediljolli.com/userfiles/files/fodepudewotuguk.pdfIn PDF document text
    • http://fatename.com/uploads/files/202109100902259627.pdfIn PDF document text
    • http://simonhoirup.dk/userfiles/file/mapujarowuwonuvebiliwukot.pdfIn PDF document text
    • https://spyboarcams.com/files/rivodetuvudofupow.pdfIn PDF document text
    • https://abicecream.ru/ckfinder/userfiles/files/finuvopalalikedoxa.pdfIn PDF document text
    • http://lindseyderence.com/userfiles/files/56244534397.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/161309097d8362---65947814971.pdfIn PDF document text
    • http://chocoenglish.com/_UploadFile/Images/file/89593331256.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/nsi64h891sma4o2ardunrchj57/farigam.pdfIn PDF document text
    • http://jucal.es/images/file/wakofozigunoladizet.pdfIn PDF document text
    • https://hopadive.cz/ckfinder/userfiles/files/52453072719.pdfIn PDF document text
    • http://www.its-dph.cz/admin/fckeditor/editor/userfiles/file/nemasakekufuzunufupovop.pdfIn PDF document text
    • http://membranekeyboard.pl/_data/file/sagilivowenexaki.pdfIn PDF document text
    • https://bimstudioinc.com/media/files/53297013765.pdfIn PDF document text
    • https://mobilpetrol.olajpark.hu/files/files/luvafafefeloveforug.pdfIn PDF document text
    • https://history.tlshaa.org.tw/ckfinder/userfiles/files/nujujogisef.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=nova+launcher+carPDF 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_off00010514.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10514 18192 bytes
SHA-256: 25a5e9b50f1622502fae715142e3e6bd55aa82e207d6942066688d550e172d1e
font_01_sfnt_off0001340a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1340A 10112 bytes
SHA-256: 40676ae783f380219ce382bdfeb75c724e3db06ba22c38e9954e4d1898f37476
font_02_sfnt_off00014a91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A91 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1