Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c3dfd8032c94f24…

MALICIOUS

PDF

77.6 KB Created: 2021-09-08 18:10:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: e8437ef0b7f911c7c326c6ecde8048a5 SHA-1: 3654c2aab4348d55e7633fbccabc264021a40f95 SHA-256: 5c3dfd8032c94f2440a0435a59e203ca5a88971e89bae46a9a3f086fe7f3919a
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, but the heuristic firings and URL analysis confirm its nature as a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://immsac.pe/sgi_userfiles/userfiles/files/70979623786.pdf In PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/16134b6a499778---63955256566.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/alhfaq9rbdinb5ikjd0u74gg7u/regemotamazamikenopon.pdfIn PDF document text
    • http://bbpcosmetics.com/admin/upFiles/2021-9/file/majupuvaguvum.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613616ecceecb---paxalos.pdfIn PDF document text
    • http://schoonhovensvrouwenkoor.nl/ckfinder/userfiles/files/borapesebanutomewazados.pdfIn PDF document text
    • http://wxbeimei.cn/upload/ckimg/files/202109071508272954.pdfIn PDF document text
    • http://tieuhocsongphuong.hoaiduc.edu.vn/ckfinder/userfiles/files/48596031107.pdfIn PDF document text
    • http://tetrafluoro.com/upload/files/93117382876.pdfIn PDF document text
    • https://adci.vn/data/upload/file/60325838912.pdfIn PDF document text
    • http://rc-modeller.se/images/file///46707396811.pdfIn PDF document text
    • http://saatgaamkansarasamaj.com/admin/uploads/files/dexexojereligakop.pdfIn PDF document text
    • http://purplebyanki-com.bvirani.com/ckfinder/userfiles/files/biwawazozatiminonifaxeg.pdfIn PDF document text
    • https://blnk.eu/userfiles/files/jusazufeto.pdfIn PDF document text
    • https://mercerapparelss.com/userfiles/files/nemad.pdfIn PDF document text
    • https://lazdynumokykla.lt/userfiles/file/35098450221.pdfIn PDF document text
    • http://studiolorenzino.eu/userfiles/files/desagawav.pdfIn PDF document text
    • http://ldksolar-officialliquidation.com/userfiles/files/69539256888.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/16133016da7990---40556866493.pdfIn PDF document text
    • http://fernandopelosini.it/userfiles/files/jovar.pdfIn PDF document text
    • http://isystemlab.com/admin/ckfinder/userfiles/files/72926303004.pdfIn PDF document text
    • http://penzionnakrizankach.cz/ckfinder/userfiles/files/gobobivov.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/99598bf6faa15d2fdb68ffeea6ce25d2/pezibizewasikorapumobob.pdfIn PDF document text
    • http://bkm-market.net/userfiles/file/xopifufivawexogofeto.pdfIn PDF document text
    • http://shangyi-pump.com/uploads/file/031823377028.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=conformateur+a+diode+pdfPDF 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_off0000c9b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9B5 10576 bytes
SHA-256: 7715f610f9fb30bc3a5e6bb61cdd66b6bf243df57cd18c1558286845dfc733dd
font_01_sfnt_off0000e1ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1CE 18104 bytes
SHA-256: 1550e1518b2d0211cd3a71d2341424963e0d15ec98f4d4ab7ad57c379c3156e4
font_02_sfnt_off00011087.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11087 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1