Malicious PDF — malware analysis report

Static analysis result for SHA-256 72c890f21a3a8f28…

MALICIOUS

PDF

71.2 KB Created: 2021-09-18 15:11:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 1592a42f7a5a182813909877a1fc5106 SHA-1: ea65869f3dcf07ede051b19e1bfad6719fa3b1b2 SHA-256: 72c890f21a3a8f2801bfcc01d4afdc35d48d352946f8e23694e64029eb449d1b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm pointing to compromised CMS uploads and disposable hosting. The embedded JavaScript likely facilitates the redirection or further payload delivery. The numerous unknown URLs suggest a broad attempt to lure victims through various domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://sambelteri.com/contents/files/39116501696.pdf In PDF document text
    • http://knupress.com/pds/editor/file/99180715683.pdfIn PDF document text
    • http://dlugopis.kbo.pl/ckfinder/userfiles/files/66706913201.pdfIn PDF document text
    • http://atol-res.pl/uploads/file/befumawogopol.pdfIn PDF document text
    • http://uktohabbarijamalta.com/files/file/lagitirulumosuvaxudi.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614237b4b415d---8531038169.pdfIn PDF document text
    • https://fullmagicweekend.com/ckfinder/userfiles/files/35397277036.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142fb7c6ac8e---bifif.pdfIn PDF document text
    • http://www.veslovani-vsb.cz/soubory/file/71682890559.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614130204ba15---nunojurobutuxu.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/b7f722be4a630a526f64f0307b43de08/fuzokinisebabumofot.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613df41847025---jufixukisu.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161377eb361ce5---99951110986.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/6b7a67929c64a450a54c9485e4fed9ad/34373788952.pdfIn PDF document text
    • https://securitydm.rs/slicice/file/baxifi.pdfIn PDF document text
    • http://nghiencuuykhoa.com/uploads/userfiles/file/molowerudewezugoga.pdfIn PDF document text
    • http://vngo-cc.vn/cooker/public/files/puzisefijonudofipelufodip.pdfIn PDF document text
    • http://czernavendeghaz.hu/admin1/file/kasiku.pdfIn PDF document text
    • http://onroerendgoedindex.nl/images/uploads/butazogidetarefekavetari.pdfIn PDF document text
    • https://konferencii.ru/js/ckfinder/userfiles/files/9840227516.pdfIn PDF document text
    • http://chuabenhxuongkhop24h.com/images/files/86333599670.pdfIn PDF document text
    • http://ecolservizinettuno.com/userfiles/files/11840690530.pdfIn PDF document text
    • http://sangjeom.com/userfiles/file///76557001531.pdfIn PDF document text
    • https://lostsoulsmemorialnj.org/wp-content/plugins/super-forms/uploads/php/files/a395e366bf33643aaedd84a8f97058c3/3305767733.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=interchange+4th+edition+level+1+student+book+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_off0000b7f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d008.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD008 11380 bytes
SHA-256: 01dd666da0e67d8ec5a2e6c83e637a7535ee365667856f0392d9ea7a6f7a0949
font_02_sfnt_off0000ea72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA72 14332 bytes
SHA-256: bf20561a8feb88f0178457294ec9d74fcbf9191705a4b6791a729014c0cb2fab