Malicious PDF — malware analysis report

Static analysis result for SHA-256 a71f4122e3c807ba…

MALICIOUS

PDF

70.8 KB Created: 2021-09-17 20:02:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a98c46f30f762b58868bec246a8040d6 SHA-1: a80e0eb0909aeb972808a4d627a4e9c303ee509c SHA-256: a71f4122e3c807bab77f4d0b5a780dae670aa973fc287adc51de20bff737096f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://crewmak.ru/uplcv?utm_term=how+to+hide+files+in+android+mobile PDF link annotation
    • http://a2hgghk.handylover.com/upload/files/32863503567.pdfIn PDF document text
    • http://uitvaartverzorgingsindex.nl/images/uploads/musedumivop.pdfIn PDF document text
    • http://riggi.ru/userfiles/file/94108637436.pdfIn PDF document text
    • http://haokunchem.cn/upload/files/62855385618.pdfIn PDF document text
    • http://wxmx.cn/upload/ckimg/files/202109031535152429.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137b6590148a---75375075692.pdfIn PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/372ed380bce2627c12fa477e16f1b972/xenutesajik.pdfIn PDF document text
    • http://duplisite.com/userfiles/file/pusetomofediludof.pdfIn PDF document text
    • http://xiangzhuan.tw/upload/files/jezobijofopugekobobo.pdfIn PDF document text
    • http://dmkert.hu/files/file/15752119107.pdfIn PDF document text
    • https://iqmuseum.mn/uploads/files/rewokunixovukikorejibaj.pdfIn PDF document text
    • https://sentralperdana.com/file/pejinitukavevovakinudem.pdfIn PDF document text
    • https://bgg.pirkitpadangas.lt/ckfinder/userfiles/files/66352814311.pdfIn PDF document text
    • http://kubabus.cz/novy-web/upload/file/dojurug.pdfIn PDF document text
    • http://dpholding.ru/uploads/files/70957434875.pdfIn PDF document text
    • http://pospatrans.cz/UserFiles/File/19309333063.pdfIn PDF document text
    • http://zatoodesign.com/userfiles/files/21809951723.pdfIn PDF document text
    • http://aloisiquadri.it/userfiles/files/19480402429.pdfIn PDF document text
    • https://llibreriaha.com/img/events/file/64793345380.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161311f6d98f57---sezavapafupavegixiv.pdfIn PDF document text
    • http://mackielaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/95876908797.pdfIn PDF document text
    • http://kxqcgs.net/filespath/files/20210911152320.pdfIn PDF document text
    • http://hockjoohin.com/admin/uploads/file/pigogaguji.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_off0000b1f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1F4 16624 bytes
SHA-256: 7bc1cfb96517c6685e476b9aa92a6d0cc90d9d13c9265e95d2fdbb423422a7c3
font_01_sfnt_off0000dc82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC82 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f499.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF499 10836 bytes
SHA-256: 2ad96687f2292b94d30a9f04b9d00c2da52bd8feae86bf0bec01de4d1bf8a594