Malicious PDF — malware analysis report

Static analysis result for SHA-256 e638b40123de3228…

MALICIOUS

PDF

76.3 KB Created: 2021-09-18 07:11:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8a8ff1bf44e52bb5cd78577b70ced7a1 SHA-1: 55d28f30065b95bc4255961b5ce39218bf14be1a SHA-256: e638b40123de322895660b37982efa83bc7c99286b8b5beeec49f6e73698072e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to various domains, many of which appear to be compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a non-clustered link farm on disposable hosting, and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' suggests links to compromised WordPress upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://infrive.ru/uplcv?utm_term=binary+decimal+hexadecimal
    • http://cpbnatation.fr/fckeditor/userfiles/file/ratamupimeladebijaga.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130f783ae827---vawutuvilot.pdf
    • http://lncxjzxxw.com/upload_fck/file/2021-9-12/20210912045730491431.pdf
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613da316ea453---8752678176.pdf
    • https://nidi.mk/ckfinder/userfiles/files/vosawokobamusepiwe.pdf
    • https://jhservice.net/imagenes/galeria/files/vaxaxitogazokebama.pdf
    • http://ellev.fr/upload/files/guvuxexupamomakiv.pdf
    • http://abwclayton.com/uploads/files/74252654753.pdf
    • http://marcth.pl/media/fck/file/25686085092.pdf
    • http://cp-tournament.org/ckfinder/userfiles/files/nodusutelubumorafaku.pdf
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/4d03cd511dc7d231880ab9694584d7af/dezotafutetososadidimude.pdf
    • https://newsru.md/upload/userfiles/files/jakijafarisa.pdf
    • http://2018.letnifestiwal.pl/ckfinder/userfiles/files/bopakewexafidewo.pdf
    • http://thestarbusan.com/FileData/ckfinder/files/20210910_6391D7593E679A33.pdf
    • http://movitecnic.com/ressource/site-image/files/74211796981.pdf
    • http://tbff-bygg.se/img/files/dofekopipamevadaji.pdf
    • http://blackhorsesc.pl/userfiles/file/87242884068.pdf
    • http://thecountryclub32055.com/userimages/xeguvujarafezikan.pdf
    • https://socialacademy.gr/wp-content/plugins/super-forms/uploads/php/files/15cbdd9cab078c837f0db5fbf4e46d4c/20837053382.pdf
    • http://maslag.eu/userfiles/file/saxutida.pdf
    • https://www.hosotte.com/ckfinder/userfiles/files/zufutanogadexajuxo.pdf
    • http://menifee.hanasushichoice.com/uploads/files/7347713909.pdf
    • http://prtourusa.com/FileData/ckfinder/files/20210904_B38BF9ED23C4C124.pdf
    • http://se-ty.ru/uploads/userfiles/file/17339164332.pdf
    • http://vibrobeton.by/pics/files/74452022405.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_off0000c9fe.bin
315bb4220e13fd53c1083e74166dfe13ca4fa18f00cbb1deaa0136a49d4365c7
pdf-font-stream PDF embedded font (sfnt) at offset 0xC9FE 10516 bytes
font_01_sfnt_off0000e1a9.bin
5ab4561a0213d01459dc7e0e7589dca6d1d546e130f60c3a5a1a930b069995b6
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1A9 16196 bytes
font_02_sfnt_off00010ae6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AE6 16792 bytes