Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8244f3d618a0c3e…

MALICIOUS

PDF

77.8 KB Created: 2021-07-06 14:02:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1b1c42fde8385a06c518bf7ad447848d SHA-1: 5f86037ed2c5bab4ffb72fbb597939dcbd11bf5c SHA-256: b8244f3d618a0c3ee1852a6e27c85ed04d93b0858af8c82a3e783a14de2e9efe
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many hosted on compromised or disposable domains, suggesting it functions as a link farm for phishing or malware distribution. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9829

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://aplus.to/userfiles/file/88705367177.pdf
    • http://alibabashipping.com/userfiles/file/suwom.pdf
    • https://edu-mate.kr/_UploadFile/Images/file/48342793038.pdf
    • https://sabagdasarov.ru/upload/file/93679274359.pdf
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076be6865d88---bokapusozaboputediwoni.pdf
    • https://arerp.kr/data/file///32947691426.pdf
    • http://jimigubellifoundation.org/clients/f/f9/f96c94eea877db95ad0a8b6fd709b1ed/File/romerufi.pdf
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160819d02cca01---20231423201.pdf
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/16088b16007931---zewatuzaxixuz.pdf
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/4f0475cb15f41beebfc1ad355df584cc/73444588357.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1608962c503ae0---74030193573.pdf
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608ee290f07fa---30759273267.pdf
    • http://esipro.fr/userfiles/file/jasepunizofifelukuv.pdf
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086e8e0809f6---77029693681.pdf
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160885b0292efd---58394397935.pdf
    • http://phongkhamducphuc.net/images/files/6844371498.pdf
    • https://www.couleurs-et-jardin.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160bf7d8b83d4f---61417658049.pdf
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/hbfie38r7bui7v53ht3d188qr6/rukiwovukotipodozed.pdf
    • https://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/66n1gqlcfn5n9c19b6ek2uubgv/bopemoronemasagemuz.pdf
    • http://traktorpulling.de/ablage/userfiles/files/57858041559.pdf
    • http://chocoenglish.com/_UploadFile/Images/file/97680573864.pdf
    • https://mszukam.pl/dat//file/76432701964.pdf
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/8e1a4fbc4b9a6766596d9d0cc1c4a854/94845113250.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160ce1685e06f5---kiruvudazapakuwuko.pdf
    • https://lightspec.ca/wp-content/plugins/super-forms/uploads/php/files/a90de61dc9362ffbd4e56b1e31c078d8/75761729640.pdf
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083337f13219---77211351872.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=happily+ever+after+cass
    • 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_off0000c83a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC83A 16792 bytes
font_01_sfnt_off0000e051.bin
ec0e9773cfb85e316b99edb72dffc1a97fccaf3d26950aafb03f01d529451dae
pdf-font-stream PDF embedded font (sfnt) at offset 0xE051 10420 bytes
font_02_sfnt_off0000f80f.bin
bd3561faf2e4ccdf7a5c0791438ebf1ccdac5a0049684ac64bc6b75c43881f5e
pdf-font-stream PDF embedded font (sfnt) at offset 0xF80F 19544 bytes