Malicious PDF — malware analysis report

Static analysis result for SHA-256 b20cf1245d4a2a1c…

MALICIOUS

PDF

119.9 KB Created: 2021-07-01 20:22:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8b2a2f143ff845cbf651c787b4cd6a61 SHA-1: bcde249c2695d81aa28ec55e58250e33706a98b9 SHA-256: b20cf1245d4a2a1c306d07712b37550fe3817e4b4fa90d176480a03c965b8f01
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to lure users to malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, and the document body was unreadable, so the exact nature of the payload or lure remains undetermined.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 5

  • 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://www.alex-vasilkov.ru/images/wisdom/file/24259433641.pdf
    • http://bet-balance.com/userfiles/file/2112917213.pdf
    • http://fontanarosaserigrafia.it/userfiles/file/sajomurolete.pdf
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609ecd2d38612---14228719402.pdf
    • http://firewheels.pe/userfiles/file/kibemoza.pdf
    • https://www.scilights.com/wp-content/plugins/super-forms/uploads/php/files/b9082fa560886fac57555119dd3aa173/98141777232.pdf
    • http://bjallstar.com/upload/file/95042292042.pdf
    • http://elitvorota.ru/f/file/63493717563.pdf
    • https://kogan-photo.ru/wp-content/plugins/super-forms/uploads/php/files/6e39ce9de23b0f419c18b74684e822db/50367075594.pdf
    • http://bud-drog.pl/userfiles/file/sivigenisisutanuwades.pdf
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/d32908583eb8ead9a90043337ef22be5/puwusefesositu.pdf
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095d1da2418b---5465474262.pdf
    • http://anhuifan.com/upload_fck/file/2021-6-30/20210630063148442320.pdf
    • https://triosms.com/userfiles/file/71714906564.pdf
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7ca9046bd4---52380621257.pdf
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/16075e31964097---13577898223.pdf
    • http://nadiadsa.org/userfiles/file/87682067459.pdf
    • https://www.lightingsolutionsal.com/wp-content/plugins/super-forms/uploads/php/files/d47e67ddaeac473c3386165c79e77ab3/mulusa.pdf
    • https://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/132f8c3b83297284637c4186b091b86b/58146795814.pdf
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160857e8129c28---lexivadawanotig.pdf
    • https://www.rydalmereprestige.com.au/wp-content/plugins/super-forms/uploads/php/files/6pdbobuht1bv4s2p4dhep8s0n8/25457205946.pdf
    • https://www.movingwithmagna.com/wp-content/plugins/super-forms/uploads/php/files/b4e01c1b5d05e4a3b1b0cee085720f1b/wepofojivite.pdf
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d276093e20---xikafugudegumulire.pdf
    • http://maility.pl_adresuserfiles/file/nekokosuzegowekaj.pdf
    • http://consol.hu/images/uploadedimages/file/guvugewikejiluvuvazopemip.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=alan+turing+the+enigma+pdf+download
    • 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_off0001705a.bin
1333df18a69568def5af70995e13d9a99f4f5cb26e190b051f8f419185e8faeb
pdf-font-stream PDF embedded font (sfnt) at offset 0x1705A 18204 bytes
font_01_sfnt_off00019f7b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x19F7B 16792 bytes
font_02_sfnt_off0001b792.bin
2411ea927dc06030b29d601aca17d708ec3e5d085d532677d4254a1f3c548409
pdf-font-stream PDF embedded font (sfnt) at offset 0x1B792 10944 bytes