Malicious PDF — malware analysis report

Static analysis result for SHA-256 2821d058e93608d1…

MALICIOUS

PDF

83.6 KB Created: 2021-09-03 21:37:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a5f806881d677a8a422af6145131e494 SHA-1: a2d406f6f2da963a6329bf35105e722aad48c98e SHA-256: 2821d058e93608d1c0b31661fe03fa87d84e83bd270589826b2e0dc84b46b198
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to compromised websites, indicating it functions as a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is unreadable binary data, providing no direct user-facing content, but the heuristic firings confirm the presence of external URIs and link farms on compromised CMS uploads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f71a174a66---36917892376.pdf In PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/160790aa66d6e2---26311143465.pdfIn PDF document text
    • http://stlnsk.ru/uploads/file/gugasokik.pdfIn PDF document text
    • http://guides2alpes.fr/uploads/file/62098801185.pdfIn PDF document text
    • https://pensiuneavalentina.ro/app/webroot/file/moxozibobudokevinomovig.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/e79155244fbd49059a97d27d15f21eaa/wemogepogaragedekaze.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2c1e17642---kajanos.pdfIn PDF document text
    • http://falconfam.com/ckfinder/userfiles/files/3241640233.pdfIn PDF document text
    • http://7tec.ru/userfiles/files/47747936335.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f23f14ed5e---66018671018.pdfIn PDF document text
    • https://f27szerviz.hu/upload/files/11378347358.pdfIn PDF document text
    • https://clarkfamilybuilders.com/home/clark/public_html/ckfinder/userfiles/files/5820561642.pdfIn PDF document text
    • http://delfosventures.net/userfiles/files/sikijexodof.pdfIn PDF document text
    • http://ohmamakitchen.com/uploads/files/gibituselazosogidanikesi.pdfIn PDF document text
    • http://nhadep30giay.com/uploads/image/files/xilabazet.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160d67ac41380d---5058203412.pdfIn PDF document text
    • http://studiospazioambiente.it/userfiles/files/sixumafow.pdfIn PDF document text
    • http://lncxjzxxw.com/upload_fck/file/2021-5-15/20210515033749293019.pdfIn PDF document text
    • http://zulassung4you.de/bilder/file/zapizoba.pdfIn PDF document text
    • https://zzhqhi.com/d/files/rabozolozejoteloxab.pdfIn PDF document text
    • http://colorfusion.us/admin/images/file/76352467856.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f8416f0a10---taxilazidomiti.pdfIn PDF document text
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/ecf676d303366f3ceaf99105859c3ba4/99318383507.pdfIn PDF document text
    • http://cuatro-pr.org/sites/default/files/file/57722164364.pdfIn PDF document text
    • https://www.ltgpartners.com/wp-content/plugins/super-forms/uploads/php/files/7508ffa62357651534d66d15c6503228/nevojagubavuxumedukul.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fe87fb68de8---viduze.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=quran+in+arabic+pdf+para+wisePDF link annotation
    • 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_off0000da15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA15 20460 bytes
SHA-256: 56539860a4bb2d0a414919a9ef15c660706cdd10aa4c814593302aabb2de683c
font_01_sfnt_off00010ff9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FF9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012810.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12810 10736 bytes
SHA-256: 0d6203a1a8801a116763e92fbdba8c950d6aa9a05bf1339c3667787964fba12e