Malicious PDF — malware analysis report

Static analysis result for SHA-256 8720b7b8e37ca861…

MALICIOUS

PDF

86.3 KB Created: 2021-10-08 05:01:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 228332cb4ac5a2d7afa982416decdbd2 SHA-1: 50f51469a4beb1e424945df659a460d853303ccd SHA-256: 8720b7b8e37ca8614c2e801765a99310699dfb8db42102ce5935973600bf02eb
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. The file contains numerous external URIs and links to compromised WordPress upload storage, suggesting it is part of a link farm designed to redirect users to malicious sites. The presence of these links and the overall detection profile indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://oniceh.ru/uplcv?utm_term=dondo+french+book+pdf
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/6731ec98fd210af584d07fbd17942632/wudusodizagekapasud.pdf
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140013d429d7---jajomagib.pdf
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c14e0568b2---76595051707.pdf
    • http://airmon.hu/images/files/27407593034.pdf
    • http://sparan-art.ru/ckfinder/userfiles/files/21553410609.pdf
    • http://amicissiapiemonteisa.it/userfiles/files/subebejudokoforuderog.pdf
    • http://votava2.altrodesign.eu/ckfinder/userfiles/files/rulazuretaveritadunepe.pdf
    • http://3234.us/data/attachment/file/17569891710.pdf
    • https://iieng.org/editor/ckfinder/userfiles/files/zekelobudifobevexeg.pdf
    • http://synphabase.ch/upload/file/96239722278.pdf
    • http://newtarrytowndeli.com/uploads/files/dekevuro.pdf
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/galezaronobuba.pdf
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/ced59a6cb0e492aef0ce6b025a27f5f9/gomemeje.pdf
    • http://ahjygjg.com/upload_fck/file/2021-9-14/20210914050536538841.pdf
    • https://vizesblokk.hu/files/file/jakuxonisazev.pdf
    • http://chretkinia.pl/userfiles/file/83859566754.pdf
    • http://cpk.by/ckfinder/userfiles/files/58117571069.pdf
    • https://elitestrategyglobal.com/wp-content/plugins/super-forms/uploads/php/files/748bee290f5ffff77c28ac0692726967/sujoguvipemip.pdf
    • https://volpatoebrum.com.br/_common/admin/scripts/ckfinder/userfiles/files/mesotogoxuludinixosomigun.pdf
    • https://demideopool.ro/ckfinder/userfiles/files/50850505167.pdf
    • http://sowiik.pl/userfiles/file/nokenoxenerikodavamus.pdf
    • http://condosworld.com/abisol1/userfiles/files/54967689812.pdf
    • http://elard-group.com/ckfinder/userfiles/files/zimipifeka.pdf
    • http://seamacros.com/upload/file/46697192898.pdf
    • 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_off0000e40f.bin
be31131032abdbc7a7f981b8d2ed02662735a6f488dae4c2e35ff8e1186f638d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE40F 10384 bytes
font_01_sfnt_off0000fb2d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB2D 16792 bytes
font_02_sfnt_off0001133f.bin
2acce5b49ac3fc4f84b45a81c8ebe14e096cdf4bd387d45074d6f40f3295fb8c
pdf-font-stream PDF embedded font (sfnt) at offset 0x1133F 21248 bytes