Malicious PDF — malware analysis report

Static analysis result for SHA-256 787dd3c536fb0bc8…

MALICIOUS

PDF

81.7 KB Created: 2021-09-09 08:54:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e16afe1fe2dc8e4786302ea1a1cf8aa7 SHA-1: 63770ecb3f06fa7ce317c25091905a5891ddee4f SHA-256: 787dd3c536fb0bc8d5f9e0a40bd16e34486a5df0f4797666bff6fea7ffe17099
156 Risk Score

Malware Insights

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

The file is a PDF that contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories. Heuristics indicate this is a link farm designed to direct users to external malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://hkxhjfc.ltd/uploads/files/20210908044722.pdf In PDF document text
    • http://land89.com/ckupload/files/xedilodusixola.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/rukidarigokejelox.pdfIn PDF document text
    • http://twfindia.in/userfiles/files/kubenirekumalinoxevorezi.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/161396ab347a01---74934932770.pdfIn PDF document text
    • https://happy-playground.gr/uploads/_uploads/files/rifofutosuwowafox.pdfIn PDF document text
    • http://thepokeluau.com/uploads/files/52046003470.pdfIn PDF document text
    • http://sculecuacumulator.ro/app/webroot/files/userfiles/files/11001358981.pdfIn PDF document text
    • https://mackbeks.com/files/file/6211569967.pdfIn PDF document text
    • https://koparieshorvathbusz.hu/files/file/banozaxig.pdfIn PDF document text
    • https://charterboatdeliverance.com/uploads/files/69034201167.pdfIn PDF document text
    • https://eklyps.net/images/file/70022614962.pdfIn PDF document text
    • http://marktoby.com/akram/know_news/admin/userfiles/file/24156834912.pdfIn PDF document text
    • https://dildendilecevirievi.com/upload/ckfinder/files/69574092381.pdfIn PDF document text
    • http://gryfarmerskie.pl/pliki_wyswig/files/28776488060.pdfIn PDF document text
    • http://sictombbi.fr/ckfinder/userfiles/files/palomazilufugomufogin.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/vtnvgp5n6gfk7870rcqh7i0i15/7972359359.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/16131692e4bc1b---roped.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/161346d51d6dfb---pugoki.pdfIn PDF document text
    • https://xeroxexpres.cz/userfiles/file/76589190531.pdfIn PDF document text
    • http://alacartedesign.de/userfiles/file/95476783610.pdfIn PDF document text
    • http://antoniolescio.net/userfiles/files/28533337658.pdfIn PDF document text
    • http://gzmingjun.com/uploadfile/files/20210909_083255.pdfIn PDF document text
    • https://art-gallery.mn/uploads/files/zeduv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=ela+worksheets+pdfPDF link annotation
    • http://zs.tom.ru/jsplugins/ckfinder/userfiles/files/begujifupubu.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_off0000dc04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC04 10560 bytes
SHA-256: ad5e2a2657dd75a13c1eed63ce8b565db62af943c9bd857ce2df9534c7464ce3
font_01_sfnt_off0000f454.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF454 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C66 17292 bytes
SHA-256: 33c9d545ac0b66f2278e49196e59522228a6d227ff083b289b0eb2303e3ac28b