Malicious PDF — malware analysis report

Static analysis result for SHA-256 50b8c4635067d08f…

MALICIOUS

PDF

85.1 KB Created: 2021-09-20 10:58:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 30754a8147de51d4e738ba2089fda1fc SHA-1: df7ba889272fdb2bb514b97d108cef39a38ab812 SHA-256: 50b8c4635067d08f1f8793d1c3032bdbb33fb5141638b6b033c767333fd18acb
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan' and an ML classifier indicating high maliciousness. The presence of numerous external URIs, many pointing to disposable hosting and exhibiting link farm characteristics, strongly suggests a phishing or malware distribution attempt. Although no scripts were explicitly extracted, the PDF structure and URI patterns are consistent with malicious documents designed to redirect users to compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://krisoc.ru/uplcv?utm_term=film+friends+reunion PDF link annotation
    • http://mabo-meccanica.eu/userfiles/files/799399302.pdfIn PDF document text
    • https://baobiachau.com/luutru/files/sokomiborevenaxepen.pdfIn PDF document text
    • http://eot.mn/uploads/userfiles/files/bugafu.pdfIn PDF document text
    • http://geometrarontani.it/userfiles/files/25668649598.pdfIn PDF document text
    • http://teknis.it/userfiles/files/13297700521.pdfIn PDF document text
    • http://zjgjqmr.com/v15/Upload/file/202192095359346.pdfIn PDF document text
    • http://thainightjob.com/ckfinder/userfiles/files/53307810587.pdfIn PDF document text
    • http://avandcie-energy.fr/ckfinder/userfiles/files/fefuxavesajazasimalox.pdfIn PDF document text
    • http://www.cda.org.hk/ckfinder/userfiles/files/rivexupasebotowudavi.pdfIn PDF document text
    • http://ph-easycome.com/userfiles/file/dasazojek.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144ff3529f4c---dipujof.pdfIn PDF document text
    • http://zjleiou.com/images/upload/File/34449489556.pdfIn PDF document text
    • https://printsolutions.printsolutions.bg/uploads/wysiwyg/files/xoxudamiwag.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/pqs9a7gjms3gtgjb79hs9r3sqm/kufadu.pdfIn PDF document text
    • https://artistaone.co/userfiles/files/rixelufoso.pdfIn PDF document text
    • https://epagneuls-bretons.fr/caningest/images/file/xivezazafix.pdfIn PDF document text
    • https://gitedu.in/ckfinder/userfiles/files/temunuwafapigixum.pdfIn PDF document text
    • http://hurtglass.pl/upload/file/59684226646.pdfIn PDF document text
    • http://lnaixi.com/userfiles/file/20210912230524_129678172.pdfIn PDF document text
    • https://goldengatetaichiqigong.com/userfiles/file/relavibanovesazabol.pdfIn PDF document text
    • http://francescofesta.it/userfiles/files/86051734639.pdfIn PDF document text
    • http://miraesusan.com/ckupload/files/pakapivulututosuxepu.pdfIn PDF document text
    • https://harmony.im/userfiles/file/22879119427.pdfIn PDF document text
    • http://minhledtran.com/luutru/files/86369815443.pdfIn PDF document text
    • https://baongochoa.com/upload/file/vitikurovoxapo.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_off0000df98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF98 20944 bytes
SHA-256: 2ddce0cd337cf0bf1a7ef5ee01333385e0f0bcecf7209de8e524b701e849b041
font_01_sfnt_off0001176c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1176C 10332 bytes
SHA-256: 2ec30b5a83d84e62367e7971e6e88c7db98c67cd307c42de3c16397b3fe0908b
font_02_sfnt_off00012e9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E9B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1