Malicious PDF — malware analysis report

Static analysis result for SHA-256 998918162ea56297…

MALICIOUS

PDF

69.8 KB Created: 2021-09-24 14:50:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 58064e0896a9e9d22360f771771dc229 SHA-1: e90d94d8b38c0692d52145b0b5b87973b7a3a881 SHA-256: 998918162ea56297a4b31d63224b42deccb176579a14f65494e2e62f4236fca4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm or phishing lure. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards techniques used for initial access via phishing and potentially embedding malicious JavaScript.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://chcial.ru/uplcv?utm_term=tonsil+adenoid+surgery PDF link annotation
    • https://www.sudoku-cool.com/ckfinder/userfiles/files/nosenogotesevamotov.pdfIn PDF document text
    • http://donovaly-ubytovanie-safran.sk/web/userfiles/file/xeliso.pdfIn PDF document text
    • https://lucky-erotic-massage-bucharest.ro/ckfinder/userfiles/files/41290107663.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fdd9e99814---sorenibe.pdfIn PDF document text
    • http://nhasachconggiao.com/luutru/files/42089458909.pdfIn PDF document text
    • https://serka.com/serka/upload/files/valenitepixabawigup.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613edf6f49811---rulikegugi.pdfIn PDF document text
    • http://acril.ru/ufiles/files/17175652135.pdfIn PDF document text
    • https://pratham.one/file/winokerepagoxewa.pdfIn PDF document text
    • http://pes.edu.mn/ckfinder/userfiles/files/98830064044.pdfIn PDF document text
    • http://stin-verdon.fr/assets/Image/files/tuxidapopirabifulu.pdfIn PDF document text
    • http://gojjang.com/uploads/files/fusejujazitavizivagejox.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/4d46effc77f5f943ea87fc9157a99941/kogowedagesopegase.pdfIn PDF document text
    • http://ibconsulting.it/userfiles/files/20706710805.pdfIn PDF document text
    • http://emanuelmlevin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/37977536135.pdfIn PDF document text
    • http://www.sloepverhuur-debiesbosch.nl/upload/files/rinanevuxitetexixogiwofe.pdfIn PDF document text
    • http://nexxosrealty.com/userfiles/files/43054331779.pdfIn PDF document text
    • http://samurairamenbar.com/uploads/files/53161238086.pdfIn PDF document text
    • https://wolfgang-photography.com/userfiles/files/fafikemug.pdfIn PDF document text
    • https://nnt52.ru/userfiles/file/76176761105.pdfIn PDF document text
    • http://metallpress.info/files/xonelojidu.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/0219bb2fa869f1d05f33ecc353f0ec98/fapav.pdfIn PDF document text
    • http://kamienneogrody.com/userfiles/file/91793498879.pdfIn PDF document text
    • http://tucholainfo.pl/userfiles/file/47151078717.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_off0000b2ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cafc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAFC 15444 bytes
SHA-256: bf58fff3e0ee78e642b302b1f5ab12778a0efea96ba7406d72fb08ee9abbb5b0
font_02_sfnt_off0000f20c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF20C 10500 bytes
SHA-256: 4ad6302837690994f2b38ac6bc2057b42281d10bdb5b6fcd6d3bdfa01716c35d