Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c928c4d77cae69a…

MALICIOUS

PDF

81.8 KB Created: 2021-09-23 15:45:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 903becd50e59c8b1e2dad06a5ed40fb0 SHA-1: dc5152026faf560803b5c8774ec9539d311f4038 SHA-256: 9c928c4d77cae69ae21b81524f89c98099382779a19e917c7cddf57ab7dd2b9b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution through these links. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with a link farm designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://chcial.ru/uplcv?utm_term=remove+icon+android PDF link annotation
    • https://kidneystonetreatment.in/userfiles/files/wibek.pdfIn PDF document text
    • http://uteambio.com/upload/files/mutidabizupitudepudufugam.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614a4143b2d03---gafupudajebe.pdfIn PDF document text
    • http://oralrem.kz/ckfinder/userfiles/files/xetubejaze.pdfIn PDF document text
    • http://www.saaegfpolis.org.br/ckfinder/userfiles/files/35000246521.pdfIn PDF document text
    • https://alkirbilaw.com/userfiles/files/79252782061.pdfIn PDF document text
    • http://energy-labels.nl/userfiles/file/36561690552.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/169c5234a942a41a97a2a71030851700/fetix.pdfIn PDF document text
    • https://mayxaydungthienlong.com/uploads/files/files/napebexusodonoxokakew.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613e61e4c312d---85025503296.pdfIn PDF document text
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1614bca38eb979---57093764214.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16132ba114f914---17323919117.pdfIn PDF document text
    • http://evola.it/userfiles/files/muxotosulagozezuwape.pdfIn PDF document text
    • https://vnycc.com/userfiles/file/tejerofow.pdfIn PDF document text
    • http://dgjinhak.kr/DATA/upload/files/202109050850108510.pdfIn PDF document text
    • https://maintogelonline2.com/contents/files/nuwixufiminetoxazoradobe.pdfIn PDF document text
    • https://implantsdentairesdesmoulins.com/upload/editor/file/fupalelimiwenisek.pdfIn PDF document text
    • http://leeharringtonhomes.com/userfiles/file/kuxonovotivatujezu.pdfIn PDF document text
    • https://afmiletisim.afmiletisimajansi.info/resimler/files/dabez.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_off0000dcd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCD3 17632 bytes
SHA-256: 0997e3d85cbcac0f95a580a3fab2f72dd72b29781b96f98d182db8353d1672f0
font_01_sfnt_off00010af1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AF1 10328 bytes
SHA-256: e248bd570ee5d2b86e5d2854f74ddd7b510ae6337c8e2a07f46b5c3336481228
font_02_sfnt_off0001222e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1222E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1