Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d850c8ecd3f0256…

MALICIOUS

PDF

69.0 KB Created: 2021-10-06 09:05:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 48c02a705a5532c59bf6fa68bec1341f SHA-1: 664c8936b6573f2c3903e9646aadbb37f8a95216 SHA-256: 8d850c8ecd3f02568e51758554f1598efb76903e67a6738b1450a4824d2dc8b4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the primary attack vector is the collection of external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://greenhousehotel.vn/uploads/image/files/39749752460.pdf
    • https://ku4ysk-9lgp4y.com/contents/files/wugabusirexikozenazuzuja.pdf
    • http://xn--9w3b11kh5l.com/ckupload/files/46613727551.pdf
    • http://tcgardening.com/userfiles/file/2021100516162173499.pdf
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16135767799b35---94541410586.pdf
    • https://myshalewell.com/userfiles/file/xutali.pdf
    • http://studiotipaldo.com/userfiles/files/25880521523.pdf
    • https://trompis-tondschungel.de/userfiles/file/65019594267.pdf
    • https://imagebrandstudio.com/userfiles/file/rezofujenetuvef.pdf
    • http://gardena.crazyrockinsushi.com/uploads/files/6339707538.pdf
    • https://floresdeserrezuela.com/aym_image/files/wedujonozulipujolom.pdf
    • https://bem-sa.com/img/file/rovudipad.pdf
    • https://bi-kiesabbau.de/cmsimple/images/file/jomuzozufasoburibe.pdf
    • http://hysansam.com/fckeditor/userfiles/image/30158771731.pdf
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/4f26b30c33c3cbe26e4f16f26ed6761b/23834022998.pdf
    • http://www.prodomasa.com/ckfinder/userfiles/files/modobozebisezavizawufarup.pdf
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615cb4ee6d331---89095789416.pdf
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/d640cf242fc509d9c998f783faca15a4/fuwusodiw.pdf
    • http://elitvorota.ru/f/file/xenufexefepakefar.pdf
    • http://shiny-baby.com/fileimage/file/naziwusetad.pdf
    • https://sesconbs.org.br/ckfinder/userfiles/files/26783749385.pdf
    • http://ysenb.kr/board/file/editor/file/teteluzirumonorej.pdf
    • https://menu2uplus.com/images/file/kafofukiwe.pdf
    • https://lawina-radom.pl/files/file/pipivararixajobetoganavu.pdf
    • http://hasdeu.md/data/userfiles/files/70180581712.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=the+best+skyblock+servers
    • 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_off0000b1a0.bin
ea31d1ee55f7a95ec80847b68c2f4f31db0842dc6080861b4b46210126d26477
pdf-font-stream PDF embedded font (sfnt) at offset 0xB1A0 14808 bytes
font_01_sfnt_off0000d6c6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD6C6 16792 bytes
font_02_sfnt_off0000eedd.bin
c2388caa2ff70400d0121b5336e90b015d557c8b3bc5cfbeb220a954ceb28b09
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEDD 10344 bytes