Malicious PDF — malware analysis report

Static analysis result for SHA-256 35875562f7d4c0bb…

MALICIOUS

PDF

88.0 KB Created: 2021-09-01 21:01:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: debcb0a4b5c796f19873c0c973a4021b SHA-1: 9d50184425f0b98d69dfafc0fdc8fb47fb0c2b0e SHA-256: 35875562f7d4c0bbd65b9873d26789d92f2fa021fde6acfd773b65c45bff70e6
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised WordPress uploads or disposable domains, indicating a likely phishing or redirection scheme. The ClamAV detection and ML classifier strongly suggest malicious intent, classifying it as Pdf.Phishing.Trojan. No scripts were extracted, but the link farm behavior is a common tactic for distributing malware or leading users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://csc-0411.com/userfiles/file/20210813232909_gxs8ft.pdf In PDF document text
    • http://gabortech.com/admin/file/59193905921.pdfIn PDF document text
    • http://linza-market.ru/upload/files/degoxojum.pdfIn PDF document text
    • https://www.pennlighting.com/wp-content/plugins/super-forms/uploads/php/files/de175027650064b0f13f9ff95fb1db08/6598628455.pdfIn PDF document text
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/160821312b67f2---navaraximixolifidubama.pdfIn PDF document text
    • https://rrrc.us/userfiles/file/tikobatawipadetoxogupik.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609573729224f---kusemodesaragudajemoxepaz.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/samawewabed.pdfIn PDF document text
    • http://dulichgiahy.com/upload/file/kajutalumaginu.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/regakogoraroluligawu.pdfIn PDF document text
    • http://greenbrier101.com/userimages/jasek.pdfIn PDF document text
    • https://truck-diagnostic.ru/wp-content/plugins/super-forms/uploads/php/files/7c39056162077d260ef8c3ee267bac61/8772548647.pdfIn PDF document text
    • http://skonasystems.com/userfiles/file/5307100199.pdfIn PDF document text
    • http://ztkammer.at/uploads/file/nomiwe.pdfIn PDF document text
    • http://varosom.hu/userfiles/files/31428428073.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/bcbab0f9c679f66ef6c79f660870ad83/44771649119.pdfIn PDF document text
    • http://artistalexanderkanevskywinnerinternationalaward.com/clientMedia/file/matafawewuxevugiruna.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/vulugebejutas.pdfIn PDF document text
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/e9a6b8994e3d65dac5540f91f2b00cb4/kadiruzana.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a0571dc4726---walut.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7dc48ac892---82593727430.pdfIn PDF document text
    • http://cokhibaosang.com/media/ftp/file/41650415397.pdfIn PDF document text
    • http://ingmarcofaedi.com/userfiles/files/53295707507.pdfIn PDF document text
    • https://gilbertems.com/videos/file/44310937379.pdfIn PDF document text
    • http://sisparts.pl/zdjecia/fck/file/62420984674.pdfIn PDF document text
    • http://medica-brno.com/files/wepoxovujojogorodejaw.pdfIn PDF document text
    • http://neonatal-surgery.ru/userfiles/files/susezemodugiv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=exactly+right+meaningPDF 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_off0000f5e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5E3 16984 bytes
SHA-256: ce28b50e85f387a8d5f6a8ea61c3da8a79a3bcd426cd9e6a4c64a6224676f143
font_01_sfnt_off0001218a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1218A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000139a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139A1 10588 bytes
SHA-256: 90b77d3bf95b49057f7519eb36f3f94341368e6c0e7bfad02894983291fbaa4a