Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc8d0b931e59f793…

MALICIOUS

PDF

87.6 KB Created: 2021-08-16 08:09:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7421c93dda74254bab359f78a374e346 SHA-1: 7979ae46897376e7d8dcd53bbe24fc60e74d21c4 SHA-256: dc8d0b931e59f79393c82b0c8c66ed8ed46b94c385686c2e35e424f442f9f083
164 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external links, many pointing to compromised WordPress sites, suggesting a link farm or phishing lure. The presence of a 'download button' heuristic further supports a social engineering attack. While no scripts were explicitly extracted, the PDF structure and link farm behavior are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9886

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://synerhu.ru/uplcv?utm_term=free+goal+tracking+thermometer+template
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160ff583eb1351---50397019780.pdf
    • http://sgo-bage.com/public/files/files/32942555794.pdf
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607d5a71b3e49---dowodisufob.pdf
    • https://bodymason.com/user_uploads/files/dopegitomesoba.pdf
    • http://kopdesign.nl/userfiles/file/61639189491.pdf
    • https://aluminiosarla.com/userfiles_arla/files/5062322957.pdf
    • http://classtool.info/upload/files/malabidoje.pdf
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/vruigb5tlfauppqnmg1adaak53/29707821870.pdf
    • https://marblobathware.com/app/webroot/img/files/xiwinewawul.pdf
    • http://axwelindia.com/uploads/41046498116.pdf
    • http://robalton.es/Albums/images/file///94943914608.pdf
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160887ade20978---juzuribebijojukaguzifexo.pdf
    • http://endustriyelkiralama.com/wp-content/plugins/super-forms/uploads/php/files/fij9a3mjg468l8lg4rvullivt6/88023911283.pdf
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/abf77ad9c6921d32460ba1e3ca6c1c28/64791069713.pdf
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160b45ccaa9372---59207464138.pdf
    • http://becskeicsodajo.hu/admin/fck_upload/file/82264097932.pdf
    • http://cokhihoaiduc.com/uploads/files/nuvusuvikedil.pdf
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/724c11bf58908cf0ace61d6badeb3eaa/50760233452.pdf
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/rotipibulilafuroguwibit.pdf
    • https://kfmaccounting.com/webroot/img/content/files/bokowemekufebivejako.pdf
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/160b3a64224f4f---42218047182.pdf
    • http://evolutionchonburi.com/userfiles/files/78892195045.pdf
    • http://superpart.com/files/12677210952.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d80e98b5c8---11691083894.pdf
    • http://rickgrisolia.com/userfiles/files/25582009218.pdf
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/36770a6964223ae6225a8578af716339/83976554519.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_off0000efec.bin
cfd7f6da133dbd7e3207a2c479c30931ad27191f38e6f1f15030a0379319c966
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFEC 10720 bytes
font_01_sfnt_off00010844.bin
8ab073b50a22165d657646805403458e092c6218adb7352db88b3aa2db5ac9a0
pdf-font-stream PDF embedded font (sfnt) at offset 0x10844 17908 bytes
font_02_sfnt_off00013743.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13743 16792 bytes