Malicious PDF — malware analysis report

Static analysis result for SHA-256 c38ecb7f0436a611…

MALICIOUS

PDF

91.8 KB Created: 2021-06-27 22:18:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ead4fb3d67ab33df74f7b8781351f83d SHA-1: a5ed882188e1eec541015033b5feacaf9295ab81 SHA-256: c38ecb7f0436a6118ebedceab7acc1c646397e7366d5decea5efc1caf4c93717
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, many hosted on compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the PDF structure point towards a phishing or malware distribution campaign, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 https://chcial.ru/uplcv?utm_term=list+the+general+functions+of+the+cerebrum
    • https://isleo.com/i_photos/file/boduxizugimivafugesapizu.pdf
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608dea6334f56---larilumujakewelunofamutev.pdf
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/84fa02fae8b91eb14c5c9e932e1c567b/zutizobizimuvuvikevo.pdf
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/28qarui22kj3pclnt9kar2thb2/fowomulozirenodewuruteta.pdf
    • http://aceonlinementors.com/userfiles/file/35158339925.pdf
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/3d316284cc7a29f2172f31e04ac4e347/99114504995.pdf
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/96423b08b747d3f74fc2f66e610db648/wajifo.pdf
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/7884a59927ee7a42f97c3d390c92280d/5452757634.pdf
    • http://copelandreunionla.com/clients/6/66/66f6f3de7053633686652f51c4c00696/File/ribewesawezi.pdf
    • http://wijnhuis-vaessen.nl/site/data/ws/files/gamerazimemelopekowu.pdf
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160789de06120c---zivusuvomoxukupenatom.pdf
    • http://adaviestransportltd.com/userfiles/file/bojilamusozilib.pdf
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16090ffe285b91---97359481452.pdf
    • https://dolcezzecaffe.it/file/35641203814.pdf
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608ef6a5e54d8---64225819847.pdf
    • http://esthebel.de/userfiles/file/sofuk.pdf
    • https://www.northwoodmedical.ca/wp-content/plugins/super-forms/uploads/php/files/92o6r9i6vth1dgtf2fofdc0039/depizuzokasaf.pdf
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089c7bc7674b---90022221971.pdf
    • http://myshopekerala.com/userfiles/file/20070938088.pdf
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ad6515c2bb2---kitusuxa.pdf
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160892cd0d99e5---94343167456.pdf
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1608bee8735581---vekunufotatikamegavufowu.pdf
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/hufaf3j4u44ror4teq9p7odiaa/lurop.pdf
    • https://singaporenotarypublic.com/wp-content/plugins/super-forms/uploads/php/files/666bf23d3c0b1e91f56177014a6c372c/wonedevaxowofa.pdf
    • 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_off00010445.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10445 16792 bytes
font_01_sfnt_off00011c5c.bin
18853bd7eafdf63e262029ff4b8292509c1ca0229c6585e7f104c264427d6467
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C5C 10980 bytes
font_02_sfnt_off000135a6.bin
60096ebef787711249a50590c2141df4361ea3d1e79f53a421e1142b0cd32ece
pdf-font-stream PDF embedded font (sfnt) at offset 0x135A6 16900 bytes