Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb68d2134f26c24d…

MALICIOUS

PDF

81.3 KB Created: 2021-08-23 09:55:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4e928199efe473e4cea774e5d8b6dda1 SHA-1: c1e9a28c020f5d18113d885b3fd21c47adcabf70 SHA-256: cb68d2134f26c24d57aaeb120a85ce250310c8b2f338c403240f839a0923ef6e
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to host and distribute links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ed89caaa53---57321452023.pdf
    • http://ecole.ru/text/images/file/39679533583.pdf
    • http://learningkey.org/userfiles/fixomawuvajizetelo.pdf
    • https://caraudioshop.ro/mm/file/bepadavur.pdf
    • http://hytechcommunications.com/userfiles/file/19625559810.pdf
    • http://amy-tsai.com/images_express/userfiles/files/92013996803.pdf
    • https://www.eziblank.com/wp-content/plugins/super-forms/uploads/php/files/5k5lid45pggmae4ut3lo0lhfm2/mupune.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd0200a084f---12809383652.pdf
    • https://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/gq22v2udfqah279n00sgqsbat9/38855297534.pdf
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/160746216ae060---41686919774.pdf
    • https://alkathirilaw.com/userfiles/files/lumigagujeno.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095bec49e760---fevobepexelisuvepekiludiv.pdf
    • http://licausi.it/userfiles/files/girudix.pdf
    • http://mixline.ru/img/lib/file/motikuloxa.pdf
    • https://nguyenhungstone.com/uploads/image/files/28373866829.pdf
    • http://lncxjzxxw.com/upload_fck/file/2021-8-14/20210814074710588742.pdf
    • http://efuturesthai.com/uploads/file/7186304246.pdf
    • https://vrindaindia.com/php/joseph/uploads/file/tilebivo.pdf
    • https://barrierball.cl/ckfinder/userfiles/files/44938403722.pdf
    • http://lottfamilyreunion.com/clients/878857/File/folegigonometopukinem.pdf
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072060a07c00---94450280291.pdf
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/16072309d8a1c6---fijixezasedasugukudevujax.pdf
    • http://ronaldtan.nl/images/photo/ledobirixesobunozov.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=sexual+chronicles+of+a+french+2012
    • 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_off0000d115.bin
ad91165bdeac0e441c7101665afa2e16b68a3ce8d02ac93b6a68c2fb0ae03490
pdf-font-stream PDF embedded font (sfnt) at offset 0xD115 20388 bytes
font_01_sfnt_off000102cd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x102CD 16792 bytes
font_02_sfnt_off00011ae4.bin
36d67d7152aa1f887b15a999e5a65c924bc86ebc3b5c6f2b4cb76b081411e835
pdf-font-stream PDF embedded font (sfnt) at offset 0x11AE4 10904 bytes