Malicious PDF — malware analysis report

Static analysis result for SHA-256 d52a41b25a7f8359…

MALICIOUS

PDF

88.5 KB Created: 2021-09-12 01:49:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 60e6aaae0dee1b9b060f5ba601dcfb2a SHA-1: 0f41ba7d457c98ced561de6d1358cc14918975e5 SHA-256: d52a41b25a7f835909e7c2b951a695600bc65f7e210573a510c1dbbb3051a71f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm on disposable hosting, indicating a phishing or SEO manipulation attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, so the primary attack vector appears to be the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://akconta.com/uploads/files/tipakibidiwuxir.pdf In PDF document text
    • https://oncallanatomist.com/ckfinder/userfiles/files/52814789158.pdfIn PDF document text
    • https://efnnma.org/files/file/83664938533.pdfIn PDF document text
    • http://kuppersbusch.hu/userfiles/files/tajedebebebozinutepok.pdfIn PDF document text
    • http://lafenicealcamo.it/userfiles/files/tuviwa.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/161352d0eafa42---40299657680.pdfIn PDF document text
    • http://train-in-japan.com/images/blog/file/fezajijerabadixavowif.pdfIn PDF document text
    • http://riccaassociati.eu/userfiles/files/3255017357.pdfIn PDF document text
    • http://andrelandberg.com/userfiles/file/45015100935.pdfIn PDF document text
    • http://defhjdr.friend-match.com/upload/files/97689123348.pdfIn PDF document text
    • http://zulassungsdienst4you.de/bilder/file/39658957937.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee5534bee1---67635771874.pdfIn PDF document text
    • https://www.solucionaesp.com/ckfinder/userfiles/files/31355161483.pdfIn PDF document text
    • http://domki-kopalino.pl/pliki/gerowetabanoxeb.pdfIn PDF document text
    • http://afro-safari.com/upload/files/5383308877.pdfIn PDF document text
    • http://vector-food.com/userfiles/file/75947125041.pdfIn PDF document text
    • http://songpinhao.com/userfiles/files/61512510722.pdfIn PDF document text
    • http://ellenia3.eu/userfiles/files/jaliwekuzobogikaripo.pdfIn PDF document text
    • http://agedwedfjtj.pretty-match.com/upload/files/43111986617.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f81a9cb2a7---barurowatig.pdfIn PDF document text
    • https://bodymart.in/ckfinder/userfiles/files/59833202222.pdfIn PDF document text
    • https://www.habitat-morvan.fr/ckfinder/userfiles/files/48850242321.pdfIn PDF document text
    • http://marthomaiticherukole.com/userfiles/file/rotabapapujeweko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=cars+live+wallpapersPDF 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_off0000f713.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF713 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010f2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F2A 10108 bytes
SHA-256: e0b54e239fe826d0c2eb349005fdf61416801c26b3f8481296879f5d0d3787f4
font_02_sfnt_off000125e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125E0 17956 bytes
SHA-256: 27590e5a646e6fae0439f6bab2b863614dcd1e825ad0f14ffec791f006b97d92