Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff628eb83f50f581…

MALICIOUS

PDF

78.3 KB Created: 2021-03-16 05:18:28 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 05f828f204a5e050a6141aff63230c58 SHA-1: 156eb867692e3f218dc43996428e18e2b3f33903 SHA-256: ff628eb83f50f5813f14f5bf363ad957f19208255efff05816ae59c952fdeab8
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was detected as malicious by ClamAV and an ML classifier. It contains an embedded URI and an image lure that redirects to 'https://kuzutuzo.ru/wix?keyword=how+to+use+decrypted+cache+key', suggesting a phishing or malware distribution attempt. The authoring application 'wkhtmltopdf' is noted, but no scripts were extracted for further analysis.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://kuzutuzo.ru/wix?keyword=how+to+use+decrypted+cache+key PDF link annotation
    • http://saduzemed.mypressonline.com/1727563031.pdfIn PDF document text
    • http://viwesisikumebi.getenjoyment.net/access_bars.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/serogajugomiji/tutekivamilug.pdfIn PDF document text
    • https://s3.amazonaws.com/xumakomowi/tintern_abbey_pictures.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5caef247-438a-41f5-877f-8e75f288d8e1/how_do_i_connect_my_brother_hl_2270dw_printer_to_a_new_wifi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ef271be7-bbd9-4683-a037-82db091911fc/troy_bilt_4_cycle_edger_attachment.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9ef4ad4a-c7f7-4aa4-9b30-eda767ddfbc4/how_do_you_get_rid_of_back_pain_during_your_period.pdfIn PDF document text
    • https://s3.amazonaws.com/tutapaxi/zapem.pdfIn PDF document text
    • https://s3.amazonaws.com/polojuliragam/nobafubegofiwipoz.pdfIn PDF document text
    • https://s3.amazonaws.com/rodiligarexo/xijevagov.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/50affc65-9ec8-4634-8a41-9511c8cc6c7d/what_is_difference_between_statics_and_dynamics.pdfIn PDF document text
    • https://s3.amazonaws.com/juzinaramip/apkpure_hello_neighbor.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bb518432-cf12-4fab-8e90-2eccce5e029c/28895441984.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b6dadcb3-fdbf-4a6f-98d5-f3bc731e38a2/2005_nissan_murano_for_sale_by_owner.pdfIn PDF document text
    • https://s3.amazonaws.com/jazamerijekufol/smart_shopper_app.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c7758868-747d-431c-a862-183941467a9c/vepurejigizebemonigolo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cf4f5645-de5a-4ebe-a58f-7ec82cfbc898/mavinere.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f6984f24-9fc8-4dbf-b22d-58b462ee78c1/tp_link_powerline_firmware_upgrade_failed.pdfIn PDF document text
    • https://s3.amazonaws.com/fikuvine/zizogipulazofona.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4931db37-576d-49c0-9489-fb0cd4106e5e/99687604766.pdfIn PDF document text
    • https://s3.amazonaws.com/fadobirak/xeveposigadofizagib.pdfIn PDF document text
    • https://s3.amazonaws.com/rubidokezive/gikalinizije.pdfIn PDF document text
    • https://s3.amazonaws.com/wulotugadag/topology_optimization_approaches_a_comparative_review.pdfIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f654.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF654 5348 bytes
SHA-256: d981fcb22e636e5fc31c0501db0025cba4e1187fd5b3c566e9e56d21dbd44d7d
font_01_sfnt_off00010892.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10892 10324 bytes
SHA-256: 92b01a536dd254bc2a07a039f451f0d8ebc3e771a14ed05d3fdc145ab2d4bdde