Malicious PDF — malware analysis report

Static analysis result for SHA-256 0f535446f776a878…

MALICIOUS

PDF

78.4 KB Created: 2021-09-20 05:32:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5ed6bd937686c5a0292cabff0a123d77 SHA-1: 865469e72e6c59f42c3f4902c6f551869649d12c SHA-256: 0f535446f776a878816afacfedf7bedc3964dda42b41b3a35c252f3d074db933
156 Risk Score

Malware Insights

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

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 for phishing or distributing further malware. The document body is unreadable, but the heuristic firings and URL analysis confirm its role as a malicious link aggregator.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://synerhu.ru/uplcv?utm_term=ik+vijaliwala+books+pdf+in+gujarati PDF link annotation
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e86f5e2d4d---52793204398.pdfIn PDF document text
    • http://gz-chengeng.com/uploadfile/files/bebufukitixudifiw.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f3642bf1dc---17306036241.pdfIn PDF document text
    • http://wedooverseas.com/userfiles/file/88008549923.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140b1be1eaf7---valas.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1612f58159bfa1---44480776121.pdfIn PDF document text
    • https://owop.challengersports.com/userfiles/files/10492231300.pdfIn PDF document text
    • http://avtrak.ru/ckfinder/userfiles/files/zifezolokoxadeloziluziz.pdfIn PDF document text
    • https://apteka-wratislavia.pl/halatecza/userfiles/file/16593136910.pdfIn PDF document text
    • https://netwindowvn.com/uploads/userfiles/file/likifaribavam.pdfIn PDF document text
    • http://uteambio.com/upload/files/31818292724.pdfIn PDF document text
    • http://bjavc.com/filespath/files/20210914124546.pdfIn PDF document text
    • http://serramentisiciliano.it/userfiles/files/166551274.pdfIn PDF document text
    • http://indemo.pl/Image/files/mefepagu.pdfIn PDF document text
    • https://gastriklandsbf.se/UserFiles/files/tolowijo.pdfIn PDF document text
    • https://supportsystemsvainc.com/home/ssvi/public_html/ckfinder/userfiles/files/23787890364.pdfIn PDF document text
    • https://middletonchambers.com/ckfinder/userfiles/files/soxafofolixepukalulabojo.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/fd129485df85f591714ea5ead76b7f82/85397064281.pdfIn PDF document text
    • http://3mfa.com/images/editor/files/zumazikud.pdfIn PDF document text
    • http://sochi-vitrazhi.ru/ckfinder/userfiles/files/tusovalexekudisokefex.pdfIn PDF document text
    • http://immobilier-valence-agen.com/userfiles/file/tarevovebad.pdfIn PDF document text
    • https://webkapper.nl/ckfinder/userfiles/files/73888916749.pdfIn PDF document text
    • https://geneticapanama.com/userfiles/file/zodawibufevalabowonamoxug.pdfIn PDF document text
    • http://zonwering-nederland.nl/ckfinder/userfiles/files/8059925777.pdfIn PDF document text
    • http://builderall.info/userfiles/file/34651650517.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_off0000ca2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA2E 18292 bytes
SHA-256: 9af0c1d67d50209e5d87f64a4f55d2e4e19a914332905362c7108300d0727030
font_01_sfnt_off0000f99d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF99D 11104 bytes
SHA-256: 24651e61c44779583bd0296b10e01817733144ccf352a1c6fe719080783a7baf
font_02_sfnt_off00011334.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11334 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1