Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5fd3a8fd326d406…

MALICIOUS

PDF

77.8 KB Created: 2021-09-15 16:11:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1c22a0bca25bd64f64c316f134a7fbbd SHA-1: e3dbf720a6b0bb1709df559c76c7cf151d1c750b SHA-256: c5fd3a8fd326d406c1072da854b1d8ab0e56f72b72b868a76f0a34a7387f612a
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm for distributing malware. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of embedded URLs and the nature of the links suggest the document is designed to trick users into downloading further malicious payloads, likely through a phishing or social engineering pretext.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://coretry.ru/uplcv?utm_term=minecraft+free+play+download+full+version
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/c4f77cdd0600d719c4a28fca2a1f9820/fogob.pdf
    • http://minhledtran.com/luutru/files/85737396527.pdf
    • http://degrossier.nl/uploads/file/2966779213.pdf
    • http://tercovci.cz/files/file/vonawolazabozen.pdf
    • http://audyt.rowerowaszkola.pl/imgturysta/files/witaduxuzijew.pdf
    • https://unosms.us/userfiles/file/pakunupip.pdf
    • http://stagelight.pl/userfiles/files/83662445697.pdf
    • http://uptownherndon.com/uploads/files/64331407086.pdf
    • http://saaretravel.ee/images/file/salujakipok.pdf
    • http://lucidarepavimentimarmogenovaealessandria.it/userfiles/files/2895745564.pdf
    • http://humanlitech.com/files/files/papukuwes.pdf
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac6f5b7da3---fakosuginimovij.pdf
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/27105046855.pdf
    • https://taipeitccia.org/CKEdit/upload/files/gajawarosifagunomabupe.pdf
    • http://donauwell.at/userfiles/file/zujiwisasoxug.pdf
    • https://upbilbao.com/ckfinder/userfiles/files/siriwewokogolapodunewi.pdf
    • http://yibetter.com/data/files/kenububosasorutupabu.pdf
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/pf08eckcca09lfsa1lotti36mr/57347491692.pdf
    • http://versobrokers.eu/userfiles/files/19001960692.pdf
    • http://samnakthodrahassob.com/userfiles/file/74781625445.pdf
    • https://alaskaproauto.net/nbloom/fckuploads/file/bonavaminu.pdf
    • http://healingtown.org/userData/board/file/70954461345.pdf
    • https://brtim.com/uploads/wysiwyg/files/nuvodumobamejibedip.pdf
    • https://bravo-hk.com/userfiles/file/122284589.pdf
    • http://affordableadobe.com/ckfinder/userfiles/files/18238388395.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_off0000cc9e.bin
802deb50d1ce8aa39f9c79f732fe6fb64b926e5000804fb0a99198715669bb01
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC9E 10972 bytes
font_01_sfnt_off0000e64a.bin
2a9fa0b7cbb6d676a992fdd99366ea1e309606df1e984721955fa64c1e275901
pdf-font-stream PDF embedded font (sfnt) at offset 0xE64A 16456 bytes
font_02_sfnt_off000110ef.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x110EF 16792 bytes