Malicious PDF — malware analysis report

Static analysis result for SHA-256 f428d64521938d7c…

MALICIOUS

PDF

88.0 KB Created: 2021-07-21 10:00:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 36c4b34aa062cf79beb04aa30829149f SHA-1: 353a66c80c44b4b012ab4dada53060b6c032f99b SHA-256: f428d64521938d7c4f66db2e6e8c7d463e4c0227869148dbadb96722d12566d1
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with multiple URLs pointing to compromised or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of external URIs and a link farm structure strongly supports the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/b0a022f339890ef0c07ac248c2509b9a/4880780119.pdf In PDF document text
    • http://lso-msm.fr/userfiles/file/28546534694.pdfIn PDF document text
    • https://fultoys.com/userfiles/rutoxulefenorot.pdfIn PDF document text
    • http://srividyaastrology.com/userfiles/file/remaboturapudipuziniloju.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aada2569db6---joruzaxawexefesupuvaj.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b363b37e1b0---bativagi.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1609d293cc3ee3---34116704214.pdfIn PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/1offvnh1ti9b7cjsrkfklnifg2/nesokumumup.pdfIn PDF document text
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d821bb10ff4---dapanusa.pdfIn PDF document text
    • http://artospace.com/pics/file/gilat.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/e6ae4c8214d532e2692e0f307456a143/40322629123.pdfIn PDF document text
    • http://xn----8sbxab3abskk3a2j.xn--p1ai/media/file/71522781826.pdfIn PDF document text
    • https://www.movingwithmagna.com/wp-content/plugins/super-forms/uploads/php/files/adce62e637519571a2fcfa0c3070cfe9/64706647188.pdfIn PDF document text
    • http://cbelmira.com/wp-content/plugins/super-forms/uploads/php/files/havq8p1uc1suf6ggs8actsgvi1/setejovobuzufekute.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160abda1ea0fe0---tepes.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba2e7ca3c6c---96580561893.pdfIn PDF document text
    • http://polesprogettazioni.com/userfiles/files/29053125102.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/2rmh8ekamq19ufoe1mla163a53/70382808310.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609257722b803---rewaguvilebelupoj.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/u1viat1tf31q33s3r4q37fd4r0/55505086578.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/16073587fe6a41---10425646402.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2977901110---87431948257.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/bf86571c57c9ab499a9758efd22b0a8e/xamenitot.pdfIn PDF document text
    • http://vipnjl.com/userfiles/files/vezasuvaronik.pdfIn PDF document text
    • https://rozgarnetwork.com/ckfinder/userfiles/files/22874388040.pdfIn PDF document text
    • http://colorfulmedia.de/fotki/fotki/file/xebopobuzovojoruxaj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+compress+a+pdf+to+make+it+smallerPDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f77bed022bc---jasovifudet.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_off0000f45c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF45C 10848 bytes
SHA-256: 67734d6a592dcb389f9241e09d1fffb4cf7252ed7aa3a3a861292aa9252efb93
font_01_sfnt_off00010d73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D73 17232 bytes
SHA-256: 036ea81e332c5fc97262318de505746e6731230f789fd7dcf7b25a9140605d25
font_02_sfnt_off00013a6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A6C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1