Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c50f8ce5237e435…

MALICIOUS

PDF

94.7 KB Created: 2021-07-19 13:01:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 91b406c022c05982fc9cf1e9607dda52 SHA-1: a94700f7e4dfc4dacc2e76992791a40096fde03a SHA-256: 5c50f8ce5237e435794c85e846fd44e3159e45ee651852e53fdaca7151fd4228
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

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://sunwayhk.com/louis/STARKGROUP/ckfinder/userfiles/files/60367336885.pdf
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/00a2f799ac8618deeca1ae49a28aea3a/33306999824.pdf
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/m5rbncu3eusp3dn34i8ptktkhr/4886096080.pdf
    • http://1960vonsteuben.com/clients/d/df/dfb5e1b83ea85bfdc5ef1da934264264/File/waritojimokuxojug.pdf
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609df3b406156---98763430737.pdf
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/c1pdfs5mj2je17hcph5ga2cco7/wegarawifemu.pdf
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ae2ecda4fbb---wiwutavibisarupat.pdf
    • https://arnetbilgisayar.com/upload/ckfinder/files/wetokininuv.pdf
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/tojisuruxudufuwinakizu.pdf
    • http://washchienluoc.com/upload/file/94478316288.pdf
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/51719224398.pdf
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/u9mo876atok0otg1f7h1a47650/wofigiduzegasuruwifa.pdf
    • https://francoisdaulte.com/ckfinder/userfiles/files/vopojola.pdf
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/160e95a23bc530---xadew.pdf
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/g1bnh18hsvnv8roq5trm7m4a63/gowezul.pdf
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c495f79870a---54881790.pdf
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c16be29e0f6---82318994653.pdf
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5df75006e9---63644584395.pdf
    • http://centralgiving.com/media/userfiles/file/funawerasawo.pdf
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/160798d00766a5---84415967242.pdf
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/df7a322bcb2c20b725c8948cf11dfddb/kotovivojuvowopovuwij.pdf
    • http://www.thaiboat.net/image/upload/File/35813128238.pdf
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/1g7j9k1v0mi6a0ce7qe8jati2u/54610261025.pdf
    • http://jaika.in/images/documents/files/nesinopudoketepusefoxum.pdf
    • https://lastcallslc.com/wp-content/plugins/super-forms/uploads/php/files/9c777029318b5d73f3b253b564d7e374/69800005406.pdf
    • http://selfmadefilms.nl/userfiles/files/kovug.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=pay+with+rewards
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001113c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1113C 16792 bytes
font_01_sfnt_off00012953.bin
bd6638062dc63a065ed117182476bbd4c3e411aff5ddb2a1221bfcc218efa62f
pdf-font-stream PDF embedded font (sfnt) at offset 0x12953 10276 bytes
font_02_sfnt_off000140ac.bin
8af13bdfdad035afb78445af1b2c80c0daf80543fa0fc0dda925f766fd1fb97c
pdf-font-stream PDF embedded font (sfnt) at offset 0x140AC 17236 bytes