Malicious PDF — malware analysis report

Static analysis result for SHA-256 85237f65617e9035…

MALICIOUS

PDF

81.8 KB Created: 2021-09-12 07:32:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f6dd92918f01a041a0808ea10e175499 SHA-1: e245be817f3e2a95d3896f138eb0183b06220b7b SHA-256: 85237f65617e903567fbeebe5a591e99d83080bf954b878019d6dc2b9d684dfb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b3dfa61280---fikorukapak.pdf In PDF document text
    • https://istruttorecinofilo.it/userfiles/file/vizakinutanopok.pdfIn PDF document text
    • https://manhalhealing.com/userfiles/file/4759548005.pdfIn PDF document text
    • https://jeevandeepspecialcare.com/ckeditor/ckfinder/userfiles/files/32617022565.pdfIn PDF document text
    • http://safires.cz/ckfinder/userfiles/files/modikotelusajitimid.pdfIn PDF document text
    • http://harckocsik.hu/userfiles/file/fofutazetatemifoju.pdfIn PDF document text
    • http://hattingtoemrerogsnedker.dk/userfiles/file/xusujerovimuzelejijuguk.pdfIn PDF document text
    • http://dansecyr.ca/pdf/file/94099676449.pdfIn PDF document text
    • http://diamant-x.sk/UserFiles/file/jexolusufutozo.pdfIn PDF document text
    • https://micsys.in/userfiles/file/20568811771.pdfIn PDF document text
    • https://hglobaltourb2c.com/FileData/ckfinder/files/20210905_BAB2C8DB0B31493E.pdfIn PDF document text
    • https://webdatedepot.com/userfiles/file/8675310746.pdfIn PDF document text
    • https://biorenta.lt/ckfinder/userfiles/files/betimulapimalapovu.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135f85494115---xifarusetetubiw.pdfIn PDF document text
    • https://birotex.rs/images/files/jodivabezitu.pdfIn PDF document text
    • https://suacuachuyennghiep.com/uploads/files/81271471801.pdfIn PDF document text
    • https://maintogelonline2.bet/contents/files/deturomezinekabogige.pdfIn PDF document text
    • https://datatalk.ilvzhou.com/upload/files/2021/09/202109092319351980.pdfIn PDF document text
    • http://mexxeopaint.com/upload/files/nevowaresogaxi.pdfIn PDF document text
    • http://texmet.pl/userimages/file/navid.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16139dfaf49689---foxesoxifinerowuk.pdfIn PDF document text
    • https://bursac.net/userfiles/file/kibidejuvolezesap.pdfIn PDF document text
    • http://winteringlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rufatewuvokapitiniz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=need+to+remove+password+from+pdf+filePDF 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_off0000db65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB65 17824 bytes
SHA-256: 13bb050461cfdc072a7f18920538e0f5bd1b8bdca794b714001defa57031c358
font_01_sfnt_off000108ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108FF 10684 bytes
SHA-256: 4a3084b45a86c36d1e5c304f8667bd6a117556e9de1b3fe63f2ae77e0d61b604
font_02_sfnt_off00012194.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12194 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1