Malicious PDF — malware analysis report

Static analysis result for SHA-256 81bcdeeedaac02a9…

MALICIOUS

PDF

77.0 KB Created: 2021-09-24 11:50:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 14a987284d59628d75510f298ce6de80 SHA-1: 20c1004b8d4840045cacc916d9bb17f8971c2508 SHA-256: 81bcdeeedaac02a911f928f6c4c0a8d66badfbebda327712ea68f05013dcc80f
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. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery through these links. No scripts were extracted, but the structure and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 http://kolkandkolkdesign.com/site/data/ws/files/65611678033.pdf In PDF document text
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/6f490581c2352027934798349d23d246/91869186352.pdfIn PDF document text
    • http://xmzhj.com/UserFiles/file/mevaw.pdfIn PDF document text
    • http://baoveantam.org/upload/files/xusur.pdfIn PDF document text
    • http://exclusivelimoservice.com/ckfinder/userfiles/files/35366637130.pdfIn PDF document text
    • https://derechosenred.org/aym_image/files/rudajikikasigetususim.pdfIn PDF document text
    • http://erex.hu/upload/file/xuposetakasi.pdfIn PDF document text
    • https://matfplayer.com/calisma2/files/uploads/37007812560.pdfIn PDF document text
    • http://anabakorea.jp/userfiles/file/modukoxeruxisazijo.pdfIn PDF document text
    • http://web5gstore.com/Files/files/midufopagabel.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/960f613e9eb45adecc901ba123ab0133/3374247476.pdfIn PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/kih5k0lequ2hu5nfes4ib5a885/13697690062.pdfIn PDF document text
    • http://szyuangang.com/UserFiles/file///xobinoni.pdfIn PDF document text
    • http://powercleanperu.com/cms_powerclean_2015/sgi_userfiles/userfiles/files/libivemowuzo.pdfIn PDF document text
    • http://talesma.com/E/file/kitiladisabitufifi.pdfIn PDF document text
    • http://ortopediaszombathely.hu/editor_up/233347329.pdfIn PDF document text
    • https://cuacuonbentre.com/upload/files/62673334689.pdfIn PDF document text
    • http://southerncross-ex.com/images/blog/file/67439002812.pdfIn PDF document text
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613b3b8a12d39---95094233972.pdfIn PDF document text
    • http://vicc.huh.hu/UserFiles/File/vubam.pdfIn PDF document text
    • https://ikima.fr/uploads/file/92041401622.pdfIn PDF document text
    • http://rajhansnursery.com/userfiles/file/23648568345.pdfIn PDF document text
    • http://bio-scan.com/userfiles/file/jugogofagarirofigiban.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=hack+game+modern+warshipsPDF 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_off0000c705.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC705 10988 bytes
SHA-256: 92393b2932280e571688409241621ea8ffed40071dad335b7b9ec7d8e53d3549
font_01_sfnt_off0000e031.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE031 17472 bytes
SHA-256: d672abddf427d41cd2908ffcddf6d208d86e3d5e184a5d9c9659aa8a5175be63
font_02_sfnt_off00010d53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D53 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1