Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac9fafafebf95e8f…

MALICIOUS

PDF

94.7 KB Created: 2021-09-23 09:04:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 135e988fd978ad0db727ca7f87ba4f35 SHA-1: c57f21267a147064124a6af5e6455c8206532c29 SHA-256: ac9fafafebf95e8f8ff0762c5798b6878eeb0d0e1b91dddd221f3a5bb033dc7a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with several URLs pointing to compromised WordPress sites or disposable hosting, suggesting a phishing or malware distribution scheme. The PDF document body was unreadable, but the presence of numerous external links strongly supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

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 http://tvoirostov.ru/ckfinder/userfiles/files/somalisasesibazuzatu.pdf In PDF document text
    • https://www.antoniopopolizio.it/ckfinder/userfiles/files/lomalosuduw.pdfIn PDF document text
    • http://dichvugiayphep.net/hinhanh_fckeditor/file/sevobudetodofivote.pdfIn PDF document text
    • https://rajaketiga.com/contents/files/10951863000.pdfIn PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/e14eb3d098e5cf2228ae6bdaa5501d66/29246363549.pdfIn PDF document text
    • http://ilkjv.com/Images/Media/files/64971072964.pdfIn PDF document text
    • http://sutipatika.hu/userfiles/files/kitofadisamifobovovugej.pdfIn PDF document text
    • http://isisthailand.org/file_media/file_image/file/14255821669.pdfIn PDF document text
    • https://evrenmentese.com/upload/ckfinder/files/renukumezoke.pdfIn PDF document text
    • http://altiro.nl/home/tjerk/file/rujoma.pdfIn PDF document text
    • http://ladispensadicampagna.it/uploads/assets/file/59311602051.pdfIn PDF document text
    • http://biznesfishki.ru/files/userfiles/files/31698694477.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac34c8f1b4---95831837638.pdfIn PDF document text
    • http://aeon-dev.com/uploads/files/202109171628208410.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16134091fe9b46---5891827764.pdfIn PDF document text
    • https://klcmekatronik.com/ckfinder/userfiles/files/61643432068.pdfIn PDF document text
    • http://refpecsbelvaros.hu/kepek/files/tolopoparawip.pdfIn PDF document text
    • https://bisleri.genefied.co/ckfinder/userfiles/files/refakuwefibitudokonaj.pdfIn PDF document text
    • http://hertzlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/96877584548.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614164a12f3b9---sujubepukovemedigozufe.pdfIn PDF document text
    • http://hockjoohin.com/admin/uploads/file/54653192352.pdfIn PDF document text
    • http://sro52.ru/uploads/files/sinatit.pdfIn PDF document text
    • https://e-fasteners.eu/media/file/54334343645.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=snapdragon+camera+apkPDF 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_off00010a95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A95 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000122a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122A7 19480 bytes
SHA-256: f439ddb495755b46828cd1c7136bc571560749efd9c4f5db08424ddda56905ee
font_02_sfnt_off0001556d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1556D 10620 bytes
SHA-256: 7d8ccca72d268d23df29ffbf9818856635affc7925b7d4ead9e53ea9f296384e