Malicious PDF — malware analysis report

Static analysis result for SHA-256 3408bb18ac157f03…

MALICIOUS

PDF

84.8 KB Created: 2021-09-12 14:00:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 107417f19ca6b8874b432781278888e1 SHA-1: 7f206abc65a5da487b3e9cb07f0c61c6cd7574a2 SHA-256: 3408bb18ac157f03537e928c83bcb836dceacb8f12121c9156c2638f8afe92f0
164 Risk Score

Malware Insights

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

The sample is a PDF containing embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or redirecting users. Several heuristics indicate the PDF acts as a link farm, pointing to compromised WordPress upload storage and disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery via the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://saipanbooking.com/FileData/ckfinder/files/20210911_A7B70F04504163CE.pdf In PDF document text
    • http://residenceraffaellotorino.com/userfiles/files/11800896024.pdfIn PDF document text
    • https://treasurehunterdetectors.solar-ovens.net/ckfinder/userfiles/files/dulizadasosoxalemupup.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/16135eafbc4bc4---gaxuretotupod.pdfIn PDF document text
    • https://nvsrolko.org/ckfinder/userfiles/files/tipoxopowes.pdfIn PDF document text
    • http://tomei4x4.jp/js/upload/files/jojeruxuxuxelexosonupopuz.pdfIn PDF document text
    • http://www.oomewatersport.nl/upload/files/bidanupivinajujisut.pdfIn PDF document text
    • https://bruceleevideos.org/images/file/60977513800.pdfIn PDF document text
    • http://clinicaveterinariasangiacomo.it/userfiles/files/52599105729.pdfIn PDF document text
    • http://kerekesvillszer.hu/UserFiles/file/nibawutu.pdfIn PDF document text
    • https://kme.pl/global/app/webroot/uploads/file/16309797315607.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613766ae7948a---nulowopakedupemefob.pdfIn PDF document text
    • http://yer-krasnodar.ru/ckfinder/userfiles/files/kegiwasezapaguwato.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/77186623817.pdfIn PDF document text
    • http://nanobubblevietnam.com/uploads/userfiles/file/jajuronezerasez.pdfIn PDF document text
    • http://www.fashiongale.ro/userfiles/files/20019460782.pdfIn PDF document text
    • https://baxsporthorses.com/userfiles/file/xixezorinopipemur.pdfIn PDF document text
    • http://solyaris.pro/admin/ckfinder/userfiles/files/38733648543.pdfIn PDF document text
    • https://reparationmobile.net/userfiles/file/bovebanog.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/9f7dcc98c427c4970d187707606ce8d9/32077468506.pdfIn PDF document text
    • http://studionegro.net/userfiles/files/43253695043.pdfIn PDF document text
    • http://kyochonbuenapark.iorderfoods.com/uploads/files/68904332054.pdfIn PDF document text
    • https://minjar.mebel18.com/uploads/files/nunebujanawimitatad.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/0133a83841e819d8cefa2fd85915a508/42543808951.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=1000+sq+feet+house+plan+3dPDF link annotation
    • 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_off0000e36f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE36F 10900 bytes
SHA-256: 36dec252476b642e7ebfad9c212c0a92f8a0cd92ef601fdba4fcf647526d5f91
font_01_sfnt_off0000fc6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC6D 18960 bytes
SHA-256: 2e4a41ea92320db4db4691951d860539ab39ba662889628b663f6398ef3b49f2
font_02_sfnt_off00012df4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DF4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1