Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b402e4577eb7cdc…

MALICIOUS

PDF

81.9 KB Created: 2021-09-21 18:51:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0e8c97198a0a218c2ee518a95c612653 SHA-1: 764c00fa07abd283bd282e3e88e25315283b4b42 SHA-256: 5b402e4577eb7cdc928abf12f8c6c3055c683db286b2882dc96abdc7ddcc4c47
236 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. The document employs social engineering lures, specifically attempting to trick users into installing a browser extension or approving an MFA prompt, which aligns with credential harvesting or session token theft. The presence of numerous external links, many hosted on potentially compromised or disposable domains, further supports the phishing and credential theft attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • MFA / one-time-code harvesting lure high SE_MFA_LURE
    Document asks for a one-time code, authenticator approval, or MFA confirmation — consistent with credential phishing kits that steal session tokens or abuse multi-factor authentication
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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 http://spbi.cz/res/file/dubotofago.pdf
    • https://bokaichenyu.com/upload/files/walemazawo.pdf
    • https://ildiko-szepsegszalon.hu/userfiles/file/92708579099.pdf
    • http://www.dean-cpa.com/files/adminpic/file/gedekubolujazilus.pdf
    • http://szjg.hu/images/file/75948198872.pdf
    • https://francois-daulte.com/ckfinder/userfiles/files/gisexesapifuboxojimewiw.pdf
    • http://podolsk-kondicionery.ru/upload_picture/file/64959070553.pdf
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16148a06344776---lofam.pdf
    • https://exlite.it/ckfinder/userfiles/files/96326711861.pdf
    • https://slide-bearing.com/d/files/71570761162.pdf
    • https://machinex-machines.com/UserFiles/File/sedavoxobizodopod.pdf
    • http://php-lounge.de/userfiles/file/57937192728.pdf
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16143eccc02662---35085128431.pdf
    • http://arucax.am/user_images/file/99024682854.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16132869adbad2---zepunonujiduzalekesa.pdf
    • http://neoneophytou.com/ckfinder/userfiles/files/wekerodizapafil.pdf
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/d5d689205362341c516777d79802a5cc/pozugesazakujir.pdf
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134551c49035---vikominomo.pdf
    • https://medbioplast.com/klucharnet/images/file/91301907773.pdf
    • http://nitecoreromania.ro/files/file/93137601183.pdf
    • http://unionasset.net/file_upload/spaw_upload/file/20210910075051.pdf
    • https://kaowei.tw/image/files/20210909_082731.pdf
    • http://apartmany.cucoriedka.sk/data/files/75503158000.pdf
    • http://nasledie-sluck.by/var/upload/file/rixalaxagojosidixobotoj.pdf
    • http://opakowania-loga.pl/zdjecia/fotki/file/sedezupebefo.pdf
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/2cc2e5f378f512fd6bf780fbfd42583a/nowisojobeno.pdf
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a864a9150e---xonivawotik.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=share+data+from+mobile+to+laptop
    • 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_off0000db04.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB04 16792 bytes
font_01_sfnt_off0000f31b.bin
d3902f2365db285f73ba8b39af8460a620a1d240af378eec55db7a5a8ffef14a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF31B 10708 bytes
font_02_sfnt_off00010b6d.bin
41ce5a2ecedcbb041ee087bb57a38cb3d2e68ccaa0297a176dc5d68e62385f7b
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B6D 18080 bytes