Malicious PDF — malware analysis report

Static analysis result for SHA-256 828e06d74a7f360d…

MALICIOUS

PDF

85.0 KB Created: 2021-09-05 06:18:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4ff98b1099fd6d900e8633879df0bb56 SHA-1: e99701810e37c089705419177f8ea0cc0d1583e1 SHA-256: 828e06d74a7f360d5c64e728682da3fb447c95da5a1da7918ae88a2bd5a9e92c
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. No scripts were extracted, but the link farm itself is the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://bolshunoff.ru/images/wysiwyg/file/99659970421.pdf
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/160909966e804d---dokenugofobebuzepegixa.pdf
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608fe4b257824---62665455145.pdf
    • http://colescastle.com/clients/875019/File/nazitenidumukubeweg.pdf
    • http://xn--oy2b9bv81anouola.com/upload/file/202107071411356922.pdf
    • http://aryajob.com/user_upload/file/98853460883.pdf
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607cd4a1688a7---69746808166.pdf
    • http://aep-tc.com/cache/fck_files/file/3370425104.pdf
    • http://africanhairbraidingsalon.com/userfiles/file/31830478828.pdf
    • https://pirkitpadangas.lt/ckfinder/userfiles/files/82696942583.pdf
    • http://xoblates.com/clients/e/e0/e08cfb93fb97b00c28394d0532709dc9/File/92067619540.pdf
    • https://artesapanaderia.xyz/aym_image/files/labapedunavolin.pdf
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/90c24590c1bdd7db4a7194cbc5f83fa5/59333668457.pdf
    • http://com123.vn/uploads/file/95831716133.pdf
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a45d453a8ec---sonop.pdf
    • https://thefertilizerproductionline.com/d/files/64340253379.pdf
    • http://hf1968.com/clients/48820/File/66741654750.pdf
    • http://mwflower.com/upimagesfile///famipidifobabakab.pdf
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/jo3p2951qej7nllj8ufpjgui77/xuzugava.pdf
    • https://twr1115.net/files/fckeditor/file/81849440503.pdf
    • http://www.klpreschool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b3d255eb3c---parowadelunurunejevezonu.pdf
    • https://www.delaneyllc.com/ckfinder/userfiles/files/tapolapipuzirizujiraxu.pdf
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/160733f0388f5e---lowerina.pdf
    • https://aodaixuan.vn/app/webroot/upload/image/files/1784491368.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=phonics+worksheets+for+2nd+grade
    • 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_off0000e4cf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4CF 16792 bytes
font_01_sfnt_off0000fce6.bin
73229ef8ed8d6768f4322d0c4f51a37b2d165c0bdcbb979eed64a328393ba1f6
pdf-font-stream PDF embedded font (sfnt) at offset 0xFCE6 11008 bytes
font_02_sfnt_off00011665.bin
28c2960e4f09e68d26a2f112eef162a79ab9f33bf22a600c1e536867dc17993f
pdf-font-stream PDF embedded font (sfnt) at offset 0x11665 18668 bytes