Malicious PDF — malware analysis report

Static analysis result for SHA-256 31c79265caa15f3d…

MALICIOUS

PDF

83.0 KB Created: 2021-09-01 00:03:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: e7c9fc97bdf272211b39028202e4311d SHA-1: 87a47b59872dd71edb478883c58b1650480bf707 SHA-256: 31c79265caa15f3ddfce8e766a9164b48adfccca3b4a52e1d33d1fa92144433f
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, pointing to numerous compromised websites and disposable hosting, likely to distribute further malicious content or phish for credentials. The embedded URLs suggest an attempt to redirect the user to external, potentially malicious, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://ritascreation.com/userfiles/file/94940293973.pdf In PDF document text
    • http://e-photo.lv/ckfinder/userfiles/files/23273178874.pdfIn PDF document text
    • https://namratalakhotia.com/userfiles/files/xulifomadeliwalejutazama.pdfIn PDF document text
    • https://www.vedaaz.com/wp-content/plugins/super-forms/uploads/php/files/27d674007d986b2aeb0d66106f3c49f0/67660599059.pdfIn PDF document text
    • http://www.videobezopasnost.ru/ckfinder/userfiles/files/jizibexuwabokukozomodamu.pdfIn PDF document text
    • https://ukdirectremovals.com/wp-content/plugins/super-forms/uploads/php/files/1e205af5b89a637be1f49e156c3022b4/33124603100.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609886d88c015---zolowovo.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfe6eda2048---26152989458.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/esm5pdaq723n7ilrf5nb5oi137/lipodapifazazujulipugi.pdfIn PDF document text
    • http://sparan-art.ru/ckfinder/userfiles/files/21601999744.pdfIn PDF document text
    • http://etcad.net/np/upfile/file/jabakiduzifikuxazo.pdfIn PDF document text
    • http://avanti-kuhni.ru/upload/files/85084220440.pdfIn PDF document text
    • https://ewastexperts.com/userfiles/files/56735072619.pdfIn PDF document text
    • https://aronabritcan.com/userfiles/file/xekinidemudosesaburawok.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/c7ba4a19962b96a67ff2d9ef8c336864/1205571309.pdfIn PDF document text
    • http://glina-master.ru/admin/ckfinder/userfiles/files/nafowigonenamet.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/5f62e76aa79a71050aeeba88669b0b8a/825407532.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16104be9095197---40614995103.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/p9mq3vkjh3c96q9jjbe236nm7k/58820511405.pdfIn PDF document text
    • http://fullcolorspandoeken.nl/userfiles/file/dexoruj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=final+cut+pro+education+pricePDF link annotation
    • 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_off0000ddbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDBC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f5d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5D3 10416 bytes
SHA-256: 1cc1bbaa41de2d9f4152d94698599f23b504b52275fcadd326ceadf0ea91db7e
font_02_sfnt_off00010d75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D75 18696 bytes
SHA-256: c207cbb6ff4539b79fbaed36ea5e19805b5b360dd8f26cdb2a72e32e86102f33