Malicious PDF — malware analysis report

Static analysis result for SHA-256 f874b2f3f3a020b4…

MALICIOUS

PDF

80.4 KB Created: 2021-09-12 21:58:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c18490b5f5f034e5c9e8ed2f71da5e90 SHA-1: 338c3ac44c40bf50b06bc8a0d686bf1eb7d58efa SHA-256: f874b2f3f3a020b4a4d37b094b656b6ec74dec885e562732a859f76afea324a2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ML classifiers and ClamAV as malicious. It functions as a link farm, containing numerous embedded URLs that point to other PDF files hosted on various domains, some of which appear to be compromised WordPress sites. The primary purpose seems to be directing users to external malicious content, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://crysiq.ru/uplcv?utm_term=how+to+use+my+sd+card+as+my+internal+storage PDF link annotation
    • https://indicaperu.com/userfiles/file/gutewuvenifijonan.pdfIn PDF document text
    • http://creative-format.com/upload/editor/files/gagefofag.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1613da7428a00f---36934914727.pdfIn PDF document text
    • http://rnralpha.cz/res/file/94762829159.pdfIn PDF document text
    • https://poldercuptrofee.nl/site/admin/ckfinder/userfilesfiles/51856223800.pdfIn PDF document text
    • http://shiokuda1.com/contents/files/83191368789.pdfIn PDF document text
    • http://vicc.huh.hu/UserFiles/File/16798452465.pdfIn PDF document text
    • http://medrea.ru/upload/files/48371602299.pdfIn PDF document text
    • http://primaria-ciocirlia.ro/media/file/1886292762.pdfIn PDF document text
    • https://asfus.net/virgsurv/userfiles/file/21961660671.pdfIn PDF document text
    • https://www.chablis-gautherin.com/ckfinder/userfiles/files/45410475881.pdfIn PDF document text
    • http://ssaisarang.com/ckfinder/userfiles/files/10995698521.pdfIn PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210906/file/16309406535989.pdfIn PDF document text
    • http://cctsw.net/whly/up_files/FCK/file/20210910_142536_194.pdfIn PDF document text
    • http://marymo.ru/uploads/files/tovozokugof.pdfIn PDF document text
    • http://orderkiwicafe.com/uploads/files/bewaluxazinigoxipolebokuv.pdfIn PDF document text
    • http://www.smartusb.info/images/library/File/pafilejazukotet.pdfIn PDF document text
    • https://anitt.in/ckfinder/userfiles/files/zimuxut.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/161345af2a242e---jofefajazepozo.pdfIn PDF document text
    • http://sinoorchids.com/image/file/50740763451.pdfIn PDF document text
    • http://bellina.pl/userfiles/file/69665145183.pdfIn PDF document text
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16135ddb15365b---niwidazadit.pdfIn PDF document text
    • http://etoprosto.ru/ckfinder/userfiles/files/lewedexafetikep.pdfIn PDF document text
    • http://madinagirls.com/easydo%20v2.00/files/uploads/pisigab.pdfIn PDF document text
    • https://oancora.com/ckfinder/files/19947166609.pdfIn PDF document text
    • http://tano-cable.com/d/files/fimusasisigelepasuj.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_off0000d5f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5F4 11004 bytes
SHA-256: 1774244bde7e42ff40748486ea91eb6ecee0353e99cdbd800e990472caf2f783
font_01_sfnt_off0000ef5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF5D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001076f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1076F 16920 bytes
SHA-256: ae0fbcdb9f937b9f6335ed4e33326205d8885b6493528b2b24a79e9a0fadbb65