Malicious PDF — malware analysis report

Static analysis result for SHA-256 be16b67cf159fa0d…

MALICIOUS

PDF

78.3 KB Created: 2021-09-23 14:31:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 0e13db652e5b2426f0ea2504b9296109 SHA-1: ea9249ddf09bff5693deb055754cc12a30637496 SHA-256: be16b67cf159fa0d50c5cc7163773292ef35fa54aa91e69532a344d9f7a978ac
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, indicating a tactic to obscure the true destination of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://infrive.ru/uplcv?utm_term=cheapest+mi+phone+in+nepal PDF link annotation
    • http://sintellect.ru/Repository/file/38727813843.pdfIn PDF document text
    • http://daechienglishpark.com/ckfinder/userfiles/files/besev.pdfIn PDF document text
    • http://machin.kr/userData/board/file/10151559956.pdfIn PDF document text
    • https://acryl-bg.com/userfiles/file/87804175831.pdfIn PDF document text
    • http://euro520.net/userfiles/file/1631701691396413301.pdfIn PDF document text
    • http://solarissoft.com/img/userfiles/files/5881627566.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e64596058e---27369959309.pdfIn PDF document text
    • http://studiomanzella.com/userfiles/files/gibokixiso.pdfIn PDF document text
    • https://webmakler.org/userfiles/file/85503695274.pdfIn PDF document text
    • https://mgc.to/sites/web/upload/files/raxunetarud.pdfIn PDF document text
    • http://melvin.cz/data/sewidenuk.pdfIn PDF document text
    • http://dominopark.pl/public/upload/ckfinder/userfiles/files/43288821504.pdfIn PDF document text
    • https://at2-turbo-j3t.com/contents/files/39660125106.pdfIn PDF document text
    • https://maconlux.lu/userfiles/files/kuvanogarosumuxa.pdfIn PDF document text
    • http://fli.edu.mn/ckfinder/userfiles/files/9342169448.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/12db0802dd79b5bded5d9563c21ab21d/mabowonumoba.pdfIn PDF document text
    • http://fantasymusic.it/userfiles/files/70205394688.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/64fa655ce717e938944d868631f41a04/noxewomufalexub.pdfIn PDF document text
    • https://ingatlanfelugyelet.hu/uploads/file/ludegekuw.pdfIn PDF document text
    • http://kartywspomnien.pl/uploads/assets/file/32148479639.pdfIn PDF document text
    • https://zlatartopalovic.rs/files/memoduwuvela.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/10b1fb0485d0b736ddea69d18fa6671f/36769011870.pdfIn PDF document text
    • http://ilkyoukais.com/Images/Media/files/fafekutojija.pdfIn PDF document text
    • http://wmc21.com/ckupload/files/jopigulofemi.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_off0000d09f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD09F 10448 bytes
SHA-256: 02673ee2796fdd24cdb6fa5ae52711ee1c90bd4dad90c397c6d7d96f08fc0ef8
font_01_sfnt_off0000e828.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE828 16680 bytes
SHA-256: 3eceaec66b28c9ea8aa7c445308bca31ae72c463b83a21426d4ac70c1b52e1c6
font_02_sfnt_off00011380.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11380 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1