Malicious PDF — malware analysis report

Static analysis result for SHA-256 31bf5d13a0b27307…

MALICIOUS

PDF

74.0 KB Created: 2021-07-03 17:01:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 5bf551980a3ae04bc7f92aba9d84ecab SHA-1: a35ddcb8573258fe5d9c343c6641ae1bba9d9d9d SHA-256: 31bf5d13a0b273076156dac061ae949cc2b798fdcad28c8daf393a90ff594c03
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, many pointing to compromised WordPress sites and disposable hosting, suggesting a phishing or malware distribution campaign. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were explicitly extracted, the nature of the embedded links and the PDF structure align with techniques used to redirect users to malicious sites, potentially for credential harvesting or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

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 https://medvor.ru/uplcv?utm_term=nfs+most+wanted+money+trainer PDF link annotation
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16096fdebc1039---48386831943.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/612e7ae5fdfb7b6e1f0447e105fcbf74/bulinaditowukalag.pdfIn PDF document text
    • http://baggiez.net/userfiles/file/tinuvakabajiwuxobufug.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd458ba9b15---faboxuju.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/6o6odqjlcf1n1q56hf860isjl3/65518555359.pdfIn PDF document text
    • http://myshopekerala.com/userfiles/file/34180681138.pdfIn PDF document text
    • https://firsatpin.com/calisma2/files/uploads/36314982900.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c1261972d75---dedix.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/oca3lpl6cvrnlq7j76hoo6933v/69298841598.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d2e661d01a6---49628964005.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/3ad3e3fa886a449f15f29866824cf801/wojuvifanoxutibamolulosos.pdfIn PDF document text
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160a3a96c1b43d---fekalubutesamagutasi.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081ca688116f---lalexetiturudel.pdfIn PDF document text
    • http://lblussana.it/images/file/14528793677.pdfIn PDF document text
    • https://fototipia.hu/files/files/xeriralanokojagadenev.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/4c43e9cbdffff58410c02a2ee51d431f/lemoruxolagosuba.pdfIn PDF document text
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160a3ec5777edf---zugaxufisakopimirufas.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/7e707d0f5eb81a671d6f00c8448f9c55/jifodopepalurexeg.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/160ad5fe171e7c---58295190602.pdfIn PDF document text
    • http://royalwedding.jp/images/blog//file/36060482412.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160986e2cd4a09---92292853303.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b290373a7e---dotinuribad.pdfIn PDF document text
    • http://artistalexanderkanevskyroyalshakespeareglobetheatrelondon.com/clientMedia/file/62169250675.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a856df89d55---48495850365.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160984dee54939---ripojevakoru.pdfIn PDF document text
    • https://alarouba.com/ckfinder/userfiles/files/boreludesalepatowejezujed.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16072f7f8e214d---bokatubapin.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://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_off0000c15b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC15B 10648 bytes
SHA-256: d0ba582720181f052a7ce2bb0b5e34227ad764ad18158a1caea8dd87239ab881
font_01_sfnt_off0000d9cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9CD 15716 bytes
SHA-256: c129c6c1f2f38cfd5359e5d57e0ec77d97ce1279ff8c5095f6274b111f6937c5
font_02_sfnt_off00010245.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10245 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1