Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4ade314a20951da…

MALICIOUS

PDF

86.4 KB Created: 2021-09-14 03:47:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5b11c0765629ee9c54c19ac6da03f68a SHA-1: 3124d2cb0ff089f594c9c783517e9f35666d3bce SHA-256: a4ade314a20951da2358ec562b1ad2d8ad289eab2621d12b22facc073e2c3052
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://tercovci.cz/files/file/48466656830.pdf
    • https://leganordavigliana.it/uploads/file/72179466672.pdf
    • http://duplisite.com/userfiles/file/wunilu.pdf
    • https://cailux.lu/userfiles/files/tugezopugup.pdf
    • http://primaria-ciocirlia.ro/media/file/zunonujatefavagibib.pdf
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb69baff78---lexofofo.pdf
    • https://kermanrooz.com/img/files/lusujimukoxenajevun.pdf
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/161364292c615a---bujet.pdf
    • http://pololanna.com/user_img/files/78025671455.pdf
    • http://squash-fitness.cz/userfiles/file/39158547199.pdf
    • http://adveotec.com/img/file/80074726672.pdf
    • http://soc-in.com/data/media/files/nugawufajumipaxi.pdf
    • http://tnslib.su/userfiles/files/15225956120.pdf
    • http://sevimticaret.net/userfiles/file/67516301893.pdf
    • http://ilovehikari.com/uploads/files/8225812305.pdf
    • http://3e-recycling.ru/app/webroot/filesfiles/rugamozizadijikugatoxifa.pdf
    • http://gyn-ordi.at/myPix/file/bubaridelonam.pdf
    • https://washlounge.in/ckfinder/userfiles/files/52183691016.pdf
    • http://tantex.org/tantex/tantexuserfiles/file/nutafoku.pdf
    • http://datavincity.com/uploads/ckfinder/files/miwodimegide.pdf
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613fdbdc37879---lamovesevuvijuzugiva.pdf
    • http://goldmustang.ru/files/files/21866741126.pdf
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130ea467aafb---mazolipivejalanomin.pdf
    • https://www.karelo.com/uploads/File/35075194661.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=trucos+para+los+sims+freeplay+android
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e9cb.bin
9cc77c9e6ae52388eb650be5474c38f38a0571c9693f899e5ae9f815eeb754c1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE9CB 19124 bytes
font_01_sfnt_off00011aaf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11AAF 16792 bytes
font_02_sfnt_off000132c6.bin
3212585206b7903cacf96c2a552a09575c78d257003abbbab160170f5bea118a
pdf-font-stream PDF embedded font (sfnt) at offset 0x132C6 10860 bytes