Malicious PDF — malware analysis report

Static analysis result for SHA-256 81809c6d3444dc0d…

MALICIOUS

PDF

82.7 KB Created: 2021-09-12 15:54:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b24f8456fee655ed3c2f0c7447feda20 SHA-1: 74627242b192204db44f912d65839c5bb25e9ced SHA-256: 81809c6d3444dc0d6a89a7741bc48778a5cca3a996a8964d8b04a83704321a30
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 CMS upload directories or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://marathonroller.com/userfiles/files/sibogexufajifowukod.pdf In PDF document text
    • https://heyratacademy.ir/file/rolozidi.pdfIn PDF document text
    • http://creptiles.dk/userfiles/file/82949962944.pdfIn PDF document text
    • https://economiadecomunion.net/ckfinder/userfiles/files/47614762056.pdfIn PDF document text
    • https://huuphongplastic.vn/uploads/images/files/52138704991.pdfIn PDF document text
    • https://rougezenekar.hu/files/file/29048230375.pdfIn PDF document text
    • https://viadagio.be/userfiles/file/92650753556.pdfIn PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613469bac293a---dagipasokitu.pdfIn PDF document text
    • https://atvatextile.com/upload/ckfinder/files/39991768640.pdfIn PDF document text
    • https://radekslodkiewicz.pl/files/file/wuzomatonudafumifo.pdfIn PDF document text
    • https://xn--z4qq44i.xn--kpry57d/upload/actfiles/14729477358.pdfIn PDF document text
    • https://magicdiscoradio.com/userfiles/file/44132594258.pdfIn PDF document text
    • https://auto826.vnpec.xyz/uploads/files/35339732822.pdfIn PDF document text
    • https://iagclaims.endataclaims.com/ModCoreFilesUploaded/file/somuzesizipewe.pdfIn PDF document text
    • https://zapret-rf.org/web/img/podborky/files/50427918579.pdfIn PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c779a0fecd---33989246891.pdfIn PDF document text
    • http://geometramaurotozzi.it/userfiles/files/kumiditazivaneteren.pdfIn PDF document text
    • http://farmaciafoglia.eu/userfiles/files/96774767489.pdfIn PDF document text
    • http://mebelhotel.ru/images/news/file/74315025974.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/f3a995b59de3a0a7bdcfdab70013f40e/52492909839.pdfIn PDF document text
    • https://vhcvietnam.vn/ckeditor/images/files/42621066341.pdfIn PDF document text
    • http://montpellier-businessplan.com/mbp/upload/images/images/upload/ckfinder/48050355421.pdfIn PDF document text
    • http://thailaundry.com/imgUpload/files/xozukisavolevo.pdfIn PDF document text
    • http://indianspringhomes.net/userfiles/files/kojifubomupadikov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=redmi+note+9+pro+max+next+updatePDF 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_off0000d76a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD76A 10756 bytes
SHA-256: 0a197651deedd3b832b9a071d3453b09b7f705582040b4108c31d0c18d5ab05e
font_01_sfnt_off0000f021.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF021 20348 bytes
SHA-256: 3b0968a3fb6a0e668d402711c4ac2d60013754211638951b77d0d2b9eb62979f
font_02_sfnt_off0001250a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1250A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1