Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb18fb37ae52b3cd…

MALICIOUS

PDF

73.3 KB Created: 2021-09-06 13:09:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 4db21c9403bd6fea62563ebc56ba0ae6 SHA-1: 83c067e7d911c1d490635e51af8161cafdac4dc7 SHA-256: fb18fb37ae52b3cd90d68b458620a0b8b485ba874a0a469ee0261c6d8dd50266
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to other PDF files, many hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable binary data, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://kameleonhastanc.hu/files/file/533063596.pdf In PDF document text
    • http://wuxihemei.com/ckfinder/userfiles/files/20210630_011113.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abb6f60fe30---tojuk.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c73b9250676---36593022238.pdfIn PDF document text
    • http://preserveproperties.com/userfiles/files/65167295548.pdfIn PDF document text
    • http://beachhigh65.com/clients/879402/File/21781040488.pdfIn PDF document text
    • https://semangkabiji.com/contents//files/tenugudafowomefonumod.pdfIn PDF document text
    • https://xanbiente.de/userfiles/file/mokiwatisunubegawigi.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/8svdauujj7mjcv5eot91ek7hn7/bomumapafever.pdfIn PDF document text
    • http://tdsns.ru/userfiles/file/13617547636.pdfIn PDF document text
    • https://sonarmusic.hu/up_image/file/73943672230.pdfIn PDF document text
    • https://rtquery.reitoken.org/Coaching123/images/files/23445403224.pdfIn PDF document text
    • https://www.cittadelmiele.it/wp-content/plugins/super-forms/uploads/php/files/02a1b1b5990b92c7693e04e8b98945a7/24196450691.pdfIn PDF document text
    • http://gasthaus-steinkirchen.de/img/editor/file/57305664446.pdfIn PDF document text
    • http://regimhotelierbucuresti.com/images/userfiles/22130732551.pdfIn PDF document text
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/pk50p7op0k4ak24p2v4jlk1605/damufafifidal.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/12b2b3280a28c11b8294092b2acfec98/muduwaxasar.pdfIn PDF document text
    • http://guojingmall.com/userfiles/file///puzomurikijirus.pdfIn PDF document text
    • http://heyibnb.com/CKEdit/upload/files/78159463251.pdfIn PDF document text
    • http://harasim.cz/uploaded/files/tovomebuj.pdfIn PDF document text
    • https://bamfieldrental.com/userfiles/file/79197660606.pdfIn PDF document text
    • http://bradhelferlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gafalinuvelurerabediwonu.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/sa80bm9mci4n2ncv7m7mh0aog5/wemavozosisokuva.pdfIn PDF document text
    • http://gtlitalia.com/userfiles/files/34452582819.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/c12i426tdrd3qfg0g5j9t8f1dj/kozoxilewe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=oracle+clinical+user+guide+pdfPDF 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_off0000bac7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAC7 17024 bytes
SHA-256: c6957fd8e49d9e723aabb002d9599c49af6ba40ce3983b146b249c2d9eb9f164
font_01_sfnt_off0000e6e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6E1 10704 bytes
SHA-256: 304a38a80a07cbbf75bc3c4d5724ca45fc30522b2abf7e2b1d6571c79c6ecb13
font_02_sfnt_off0000ff56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF56 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1