Malicious PDF — malware analysis report

Static analysis result for SHA-256 af4bae43b587d39a…

MALICIOUS

PDF

75.7 KB Created: 2021-09-23 10:31:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: cdd2bb3b5b05874ea6c591a4fffeeca7 SHA-1: dcf23f5f6f26a00287f1aa61ef293594a9eb66da SHA-256: af4bae43b587d39af13c3aa49fd034d89e29a10d2a4959b02f0f363223975afa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to various domains, many of which appear to be compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of creating link farms on such sites. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9901

Heuristics 6

  • 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.
  • 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://cructi.ru/uplcv?utm_term=the+ultimate+imat+collection+pdf PDF link annotation
    • https://excore.hu/ckfinder/userfiles/files/vinijewasodoxedelofisabi.pdfIn PDF document text
    • https://gabinetpro.pl/kosmetyczka/krakow/files/94290597017.pdfIn PDF document text
    • http://indagosrl.it/userfiles/files/besataroligugexejozawawev.pdfIn PDF document text
    • http://cottoneauto.it/userfiles/files/60580178481.pdfIn PDF document text
    • https://fullprotec.com/ckfinder/userfiles/files/voxex.pdfIn PDF document text
    • https://izr.fr/files/bowekovemuginitofinabo.pdfIn PDF document text
    • http://christschoolblr.in/userfiles/file/xixitupumupazu.pdfIn PDF document text
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144da5cbb91d---pesetenikirekuj.pdfIn PDF document text
    • https://yumasri.com/assets/ckfinder/userfiles/files/nofopikulejowazanidev.pdfIn PDF document text
    • https://nusbetaja2.com/contents/files/lugixufogazuxozapojoze.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/edb7d5392c7dae9af07dab6ce530a842/gevolonepujilasuxuvuw.pdfIn PDF document text
    • http://suarezbeltran.com/aym_images/files/limikapifezafe.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144fa0f5b608---fajezutivuvimen.pdfIn PDF document text
    • http://iltorg.ru/upload/file/wogopiwo.pdfIn PDF document text
    • https://saatyapi.com/upload/ckfinder/files/81665318416.pdfIn PDF document text
    • https://tourpon.kr/FileData/ckfinder/files/20210921_ACC9EFB59FE758B6.pdfIn PDF document text
    • http://prochem.vn/images/uploads/files/kigudomopowozi.pdfIn PDF document text
    • https://hetodon.com/fckeditorfiles/file/xomepavokafafefamivog.pdfIn PDF document text
    • http://usarsenal.it/userfiles/files/zaxowo.pdfIn PDF document text
    • https://www.studiorosaliabusco.it/ckfinder/userfiles/files/11232261849.pdfIn PDF document text
    • https://terracell.pt/images/file/62494129457.pdfIn PDF document text
    • https://linhquan-group.com/upload/ck/files/dukefadigizutuxuz.pdfIn PDF document text
    • https://hyundainhapkhau.vn/upload/files/kinezu.pdfIn PDF document text
    • https://elitestrategyglobal.com/wp-content/plugins/super-forms/uploads/php/files/6f454687d300aa22b724340c725857f7/29283194885.pdfIn PDF document text
    • http://wordtmann.beckbauer.eu/ckfinder/userfiles/files/nezadojadutivawebumibo.pdfIn PDF document text
    • http://okna-stv.ru/userfiles/files/75010891813.pdfIn PDF document text
    • http://baoveantam.info/upload/files/luvibolu.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_off0000c514.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC514 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD2B 10680 bytes
SHA-256: 4f9af6caef6713474ed9ee47a880d96ef0e6107bfcb8c5bc3bce5687128a286f
font_02_sfnt_off0000f570.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF570 16708 bytes
SHA-256: 8e7f5d3d34e7ee56878c7906a121c301b645c94217049fb57a241d95e5e4d3db