Malicious PDF — malware analysis report

Static analysis result for SHA-256 55ef021d4d8b823e…

MALICIOUS

PDF

87.5 KB Created: 2021-07-06 12:25:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2ff8f7263b28ca1e97edf24cd2620c91 SHA-1: 3505be670802ee60f69fbe747cde79e40c228126 SHA-256: 55ef021d4d8b823ea7119f6d94031b510c7c6643f5b5595da31f1aa933f295b1
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress sites, which in turn host other PDF files. This suggests a tactic to distribute malicious content or phish users through SEO poisoning. The ML classifier strongly flagged this PDF as malicious, supporting the observed link farm behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c0c1d46bed1---jigikorewigij.pdf
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160d485760a522---20783406356.pdf
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160cd17427c1e5---16281347689.pdf
    • http://flemisterbauldingfamily.com/clients/8/82/82a21d9598fc66f9117a8fb7222c8fd0/File/37732081609.pdf
    • http://speaklifeiamgreatness.com/files/files/62342017363.pdf
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608817bce17a9---zegetevogefudanon.pdf
    • http://zabradli-znerezu.cz/userfiles/file/23353212660.pdf
    • https://travelsafeway.com/userfiles/file/77207591967.pdf
    • https://creativitagh.com/pevron/www/img/file/38782442678.pdf
    • https://amatnieks.com/pictures/image/sotadebakibuf.pdf
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/ce8caf0fd4487a27770fd822e106fb8a/47575581399.pdf
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/160aa5e7e53490---29613445059.pdf
    • http://neuragen.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b79b94be130---linagotudin.pdf
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/16088c4d3bac65---wulorifewumunonad.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/fd4a5c6048d6e9fd730cdd1067ee4725/rujesabokuvib.pdf
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/u8478lc4la3t8prttumvnlp64u/31731253549.pdf
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/62949782b51935e37a7103dbabdd9eb4/jufuja.pdf
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa81192bafe---dedamu.pdf
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d630888586---45839086843.pdf
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16070994d0eece---pipik.pdf
    • https://www.justgym.co.za/wp-content/plugins/super-forms/uploads/php/files/f2kam41678ulagu35i15cnesbr/8553238954.pdf
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d28dba9c9c3---bifujuxudijasufo.pdf
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5bfb30d088---xopusitekubusiwa.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=fifa+20+download+free+for+android
    • 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_off0000f4af.bin
7aab4b2400a37cc95284eec08bde45f16e99788d69ecef7e1bf6d83a4ea2cff5
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4AF 10384 bytes
font_01_sfnt_off00010c53.bin
48133bb669a6fc61ab8ba37fc21bcf17c20c124d8922e76804c878b6de0eb36a
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C53 17112 bytes
font_02_sfnt_off000138a7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x138A7 16792 bytes