Malicious PDF — malware analysis report

Static analysis result for SHA-256 c21e1ad3943dbd3a…

MALICIOUS

PDF

85.9 KB Created: 2021-06-28 07:51:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6087aa8c93d706d93949b4ce93c34eca SHA-1: 13102d16dc08d031d1cdbc489c1ac9fb0dbb5942 SHA-256: c21e1ad3943dbd3a2888e52085652e73f5baea6dab362d8e607d6a15009565af
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://kingnature.ru/files/files/tudafuvixepasolo.pdf
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160b8086088a3d---46624902249.pdf
    • http://psychoterapia-przemysl.net/img/userfiles/file/53581715591.pdf
    • https://grandhotelbulgaria.com/userfiles/file/84715802803.pdf
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/ik3qcuj0roj60tjqtj655f70ap/28296870595.pdf
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/917f71815466d8a6429d07a6e7c1dcd2/27296183823.pdf
    • https://upchealth.net/wp-content/plugins/super-forms/uploads/php/files/c4bf284899fc42518c55f080a55f3715/luzamudanofu.pdf
    • http://statewideroadservices.com/clients/879378/File/defivajup.pdf
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d5c63873043---64404731335.pdf
    • https://bestofbucerias.com/upload/file/89196255753.pdf
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/160a390cd4758d---jitejoladobaxisotejutim.pdf
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/271ca14830b7d1c6fabbf636b50baf64/pozodojawir.pdf
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/kbq9m5o4a3c0fvh8pr7qvg2apt/sinakilojoliribagegopaf.pdf
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/5dee8840600847b8dd859897f328de16/19989575256.pdf
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160c089f1931c8---konutuvujip.pdf
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/160866dc9b3d4e---62839177429.pdf
    • http://adveotec.com/img/file/nilepo.pdf
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/160a464c043b88---bosaxabujejakuzegi.pdf
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160af9aadbce2c---sedogaxevivinadiwe.pdf
    • https://moto-trend.cz/public/files/fck/file/51055283721.pdf
    • https://nowackleverkusen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b8014b41e26---pasusixonunujiwaj.pdf
    • http://solee.cn/ckfinder/userfiles/files/63595496093.pdf
    • https://zahnersatz.pl/userfiles/files/voruxiragexunifinugusa.pdf
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b27468952a7---ruvixa.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=teaching+with+the+brain+in+mind+pdf
    • 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_off0000ebba.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBBA 16792 bytes
font_01_sfnt_off000103d1.bin
a29a106e5cf7e315b0e67c1bb43a01391670ac380cc0c4fc13cb9a58997e511f
pdf-font-stream PDF embedded font (sfnt) at offset 0x103D1 10924 bytes
font_02_sfnt_off00011c8e.bin
162717503f3da71f68720b9465020968bd031e522d48de5c5f27dfdddcb32cce
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C8E 16948 bytes