Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a4b7c87b04aff83…

MALICIOUS

PDF

82.2 KB Created: 2021-09-14 08:16:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e10071de39ab5e95e03a6435524e8a1b SHA-1: 803c2b2d193f9bd7fe09e1cd67571ec7c2777445 SHA-256: 8a4b7c87b04aff8359b605946836cbcef3ee1a3b84f52d6a76942c33a401161f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this malicious intent. The ML classifier and ClamAV detection further confirm the malicious nature of the file, likely used for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://irlanc.ru/uplcv?utm_term=functional+javascript+pdf
    • https://efnnma.org/files/file/dukijiwev.pdf
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/4efccfd96cb6d30d0a98dd5ebcbb8222/bakofazunoja.pdf
    • https://konteshamamotu.com/userfiles/file/92001857211.pdf
    • http://digitalpolicycouncil.org/imagenes/file/zusajedasawuzusiwiwon.pdf
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c857f1cdb0---89972591765.pdf
    • http://seattlebestteriyaki.com/uploads/files/rusase.pdf
    • https://aitalk.vn/upload/files/juwew.pdf
    • https://jlgardner.org/home/jlg/public_html/ckfinder/userfiles/files/2550257110.pdf
    • http://globalsublimation.net/uploadfile/files/1161563264.pdf
    • http://iswii.net/ckfinder/userfiles/files/73549491665.pdf
    • https://hawkseyetravels.com/assets/ckfinder/userfiles/files/woxobatemefaridu.pdf
    • http://frangarcia.eu/upload/file/158365329.pdf
    • https://himarco.ir/basefile/himarcoir/files/rezibirerexosuvuw.pdf
    • http://sushibelovo.ru/files/porapubopabupaziverago.pdf
    • https://eletmodguru.hu/files/files/lunivemevabimilexowomuto.pdf
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613489e6d68e5---jikup.pdf
    • http://gyliver.ru/files/files/badafizug.pdf
    • http://tmtechvn.com/webroot/img/files/wevijudumixud.pdf
    • https://qualityroofinnandsuites.com/nbloom/fckuploads/file/32670904604.pdf
    • https://miet.hu/kepek/23212967922.pdf
    • https://ip-pharma.net/data/files/zurikujatagu.pdf
    • https://gornjastubica.hr/files/baluvurunenisobilutixurol.pdf
    • https://thic.net/plugin/ce1/ckfinder/userfiles/files/zimofi.pdf
    • http://kiuruvedenlukio.fi/tiedostot/file/13680181990.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_off0000dc74.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC74 16792 bytes
font_01_sfnt_off0000f48b.bin
d8847d1147d923a8a696bd8bb9178ab1f0204a47378254fa3d75fb28f1ba4635
pdf-font-stream PDF embedded font (sfnt) at offset 0xF48B 10756 bytes
font_02_sfnt_off00010d5e.bin
00d1894c36dc88a69e8ef86d4f0a3470c0479a6959f8d702e3562d3f75aa5789
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D5E 17924 bytes