Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3fc13f28ec718de…

MALICIOUS

PDF

80.4 KB Created: 2021-06-28 03:15:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 41cad5282fcea9bace50cce93897bb34 SHA-1: db259b5798745bcd0deb7e906c9ab4a1c8218222 SHA-256: a3fc13f28ec718de4f6d372770e25e59b5ed91917ef0a2aa2bbc488eb3056954
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a phishing or malware distribution lure. It functions as a link farm, with numerous URLs pointing to external sites, some of which host other PDFs. The heuristic 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' indicates that some of these links point to compromised content management system upload directories, suggesting a pattern of hosting malicious files on potentially compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 https://archism.ru/uplcv?utm_term=turn+multiple+files+into+one+pdf PDF link annotation
    • http://hk-sai.com/ckfinder/userfiles/files/lojifatakifovegofokuguda.pdfIn PDF document text
    • http://naasschoolofmotoring.ie/fckeditor/userfiles/file/73844511566.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609415133f1ef---50873609171.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1abb74cc79---difesile.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/501acqlk6qcpvbc68quipa1lvf/3420401336.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d2dab41f957---zozodulob.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a18a617859a---subexuzunitapujusoval.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/4jjpgvj2jnkjd3vnqc7im6fi77/xoravipodomuzete.pdfIn PDF document text
    • http://alexanderkanevskyartistbiography.com/clientMedia/file/81450257460.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/160ba6896cb398---35789003469.pdfIn PDF document text
    • http://ankurgroups.com/userfiles/file/12172732497.pdfIn PDF document text
    • http://photographybynami.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c85d473f287---goxenup.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/2a5d55bc74628750ecd45d1bca662ab0/tokovetenul.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608caed7d0f78---50957808793.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/8028317b02224a01c9ff1cb9c86f5f63/74997248955.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/83b11173c695c3dce1cd352ac18accd4/1962048348.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609c65fcd9d0b---50465961231.pdfIn PDF document text
    • https://eobliecky.sk/userfiles/file/pirijutudeju.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160810e8e21bd4---7497109246.pdfIn PDF document text
    • https://discovercefalu.it/_data/images/file/zufinaruve.pdfIn PDF document text
    • http://vrtaspol.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/7006573795.pdfIn PDF document text
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d0a501686c---63088948164.pdfIn PDF document text
    • 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_off0000d6e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6E0 10560 bytes
SHA-256: 233e14e8103816a64bbb32a345f14dc943d036b7893a6bcc89f0e79a735be303
font_01_sfnt_off0000eee6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEE6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000106f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106F8 17428 bytes
SHA-256: eafa09802f7ab0da833e939b311d9e142f80581153877765052f2452224d6234