Malicious PDF — malware analysis report

Static analysis result for SHA-256 735903e17dfa6d63…

MALICIOUS

PDF

73.4 KB Created: 2021-09-04 18:50:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 0b69184ab63fdefc57d9c88885b45b51 SHA-1: 1bd0a75d8ff55936c2750ae12e0f6bc573f508df SHA-256: 735903e17dfa6d6383d1af45e2229200de517134afb4744c7999a14cd17848ed
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links pointing to other PDF files hosted on various websites, many of which appear to be compromised or disposable. The ML classifier strongly indicated maliciousness, and the link farm structure suggests an attempt to lure users to malicious content. No scripts were extracted, but the overall structure points to a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/161294d552b727---togiwetiwofudazozitum.pdf In PDF document text
    • http://aftckwt.com/uploads/file/lasadorekujimilaxuxetefi.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607aa247eec01---baseruro.pdfIn PDF document text
    • http://www.aragonemprendedor.com/userfiles/files/sokabujezojus.pdfIn PDF document text
    • http://scuolascifondocortinadolomiti.it/userfiles/files/16466164840.pdfIn PDF document text
    • https://businessincasey.com.au/application/third_party/ckfinder/userfiles/files/70783593781.pdfIn PDF document text
    • https://nhorizontours.com/userfiles/files/60668336361.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609ea5addec13---9907326121.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607526237ea27---narubekazefizani.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/48e84a087e1b20ebc9954a11c7ae594e/21595712679.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/16075ed493a62a---81336299161.pdfIn PDF document text
    • http://al-farh-iq.com/upload/userfiles/file/77100489940.pdfIn PDF document text
    • http://zygzak.eu/foto_dane/wysiwyg/File/jajewe.pdfIn PDF document text
    • http://aan.kz/ckfinder/userfiles/files/xululinuxa.pdfIn PDF document text
    • http://freeorden.com/media/file/gijokuwidisupofijonevavir.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c499f744d1b---kadasowosijorifebufolud.pdfIn PDF document text
    • http://nwatchonline.net/userfiles/file/94380189032.pdfIn PDF document text
    • https://www.tahitotfalu.hu/ckfinder/userfiles/files/gavegigojalan.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/51597ba1aad348f6e4c150bf9af8f2d4/geredezolobo.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/wotose.pdfIn PDF document text
    • http://mateuszkucharski.pl/admin/file/81410029150.pdfIn PDF document text
    • http://benetworkingpro.com/ckfinder/userfiles/files/55856076386.pdfIn PDF document text
    • http://nhatnamvina.vn/rich_editor/file/nudoginudemebabufenotige.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=react+export+data+to+pdfPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000beea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEEA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d6fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6FC 16376 bytes
SHA-256: 9a577ab0611a9b28ad3ddab3b136b7fa29657820ac34edb13cf5c11136fb7c85
font_02_sfnt_off00010122.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10122 10348 bytes
SHA-256: 21e14ab74e3e380b4ce71110dbbf112ffd415347856a6512240e7c39de22c3a8