Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4d6c625f7a73b15…

MALICIOUS

PDF

87.3 KB Created: 2021-09-05 20:01:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4a7439c6364b54c19f7c82bc79acbc71 SHA-1: 6a7ce55966ba5bd66940a4384baecbfa1ada180a SHA-256: c4d6c625f7a73b15a4f1c5bc075f0eeb38d725934201705977e1c9b89a8178c1
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the presence of links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://jrpst.pl/userfiles/file/97168438003.pdf In PDF document text
    • https://autoprofi.ua/userfiles/file/gikojafip.pdfIn PDF document text
    • http://inciboya.com/resimler/site/files/gavux.pdfIn PDF document text
    • https://xn--fct8ml6mwue.tw/uploads/files/8691621578.pdfIn PDF document text
    • https://eobliecky.sk/userfiles/file/fesed.pdfIn PDF document text
    • http://midel.me/userfiles/file/58291897316.pdfIn PDF document text
    • http://slsnn.ru/content/file/80860346930.pdfIn PDF document text
    • http://malerbetrieb-malanders.de/Webseite/pics/fotos/1/file/pufewidotubadakap.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/ad5b181d798c7cfc1cfe4cfc841f1a87/dumajudopaxixof.pdfIn PDF document text
    • https://hiddencliff.kr/FileData/ckfinder/files/20210815_2370C2B4519A30A7.pdfIn PDF document text
    • https://bearings.vn/images/ckeditor/files/mexuwe.pdfIn PDF document text
    • https://thietbivesinhsonhoa.com/webroot/img/files/zukapumom.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079a408e6ec9---batexol.pdfIn PDF document text
    • https://pablohernandes.com/wp-content/plugins/super-forms/uploads/php/files/204307c1541934bcc3c1f98020117bca/vubasotamogej.pdfIn PDF document text
    • https://dotcomtravelegypt.com/userfiles/files/3412052341.pdfIn PDF document text
    • https://pinotcar.com/wp-content/plugins/super-forms/uploads/php/files/7f331014d63c99d91d301c9ab2299a48/39755523675.pdfIn PDF document text
    • http://trlgpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/44086667633.pdfIn PDF document text
    • https://nguoixunghekiev.vn/userfiles/file/zelixedokemu.pdfIn PDF document text
    • http://orosweb.hu/ckfinder/userfiles/files/74063216375.pdfIn PDF document text
    • http://krevue.cz/UserFiles/File/palaw.pdfIn PDF document text
    • http://kapsalonindex.nl/images/uploads/10396584644.pdfIn PDF document text
    • http://myafmc.com/clients/a/a5/a51d49d85de18111a3d718c63a5e5081/File/78022702769.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079a4505d8eb---3204373656.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=color+idioms+worksheet+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_off0000f120.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF120 10704 bytes
SHA-256: e5611630963c37fcca6702d4b322ade590a5b965d99e7bca1bfe0dbec4806cde
font_01_sfnt_off000109c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109C0 17440 bytes
SHA-256: b4484970b3be5ce7fe1a7e9749df8387d56fb7d93d6ce1c89ef46a48ba46b590
font_02_sfnt_off0001375c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1375C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1