Malicious PDF — malware analysis report

Static analysis result for SHA-256 6535420a548aff5b…

MALICIOUS

PDF

74.1 KB Created: 2021-09-18 09:36:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 694d2c67eef380c62b07ee8ab2ac0d88 SHA-1: 9be591a39257b880b0ba089840fa67715d3a2fe7 SHA-256: 6535420a548aff5b7146846f88c62199ec1d4154d335159ada1d0a3ed9183736
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically identified as a phishing trojan. The heuristics indicate it functions as a link farm, with multiple URLs pointing to compromised WordPress sites. These links likely serve as a distribution mechanism for further malicious content or phishing attempts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/2e8dc6642b1c47e851f5c4441ef62e73/72567515763.pdf In PDF document text
    • http://tsradviseurs.nl/mailing/images/photo/file/safudevudokab.pdfIn PDF document text
    • http://eros-arena-reutlingen.de/eros/userfiles/file/nadizexeteniwavopubedati.pdfIn PDF document text
    • http://savemaxint.com/files/file/20001301811.pdfIn PDF document text
    • https://onsale.social-push.cc/data/fckeditor/files/63741034542.pdfIn PDF document text
    • http://soskuwait.com/outscapes/admin/ckeditor/uploads/ck/files/gipejatowalaveluzax.pdfIn PDF document text
    • http://marsalanoleggio.it/userfiles/files/woxesofazimajovuxumu.pdfIn PDF document text
    • http://sithome.com/upfiles/file/20210915183530.pdfIn PDF document text
    • http://donauwell.at/userfiles/file/jivojefepepib.pdfIn PDF document text
    • http://geerhannutpourreussir.be/docs/upload/files/90986165103.pdfIn PDF document text
    • http://ankurgroups.com/userfiles/file/rowopemewopotitagimosolo.pdfIn PDF document text
    • http://ivankrivanek.com/userfiles/file/28944964269.pdfIn PDF document text
    • https://istanajp.com/contents/files/wajonezex.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141ef7c6cbb2---weresipatofo.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/68798141049.pdfIn PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/8ddjurssqcp1dc8gnvm6ndpapd/3464023414.pdfIn PDF document text
    • http://skybuildinfraprojects.com/uploads/20653818464.pdfIn PDF document text
    • http://www.tivafa.hu/upload/file/jipaloj.pdfIn PDF document text
    • https://oreopay57.com/ckfinder/userfiles/files/jitoxokusisademazabosug.pdfIn PDF document text
    • http://www.oe.com.tw/ezadmin/ckfinder/userfiles/files/boxomevovirepulekanilujo.pdfIn PDF document text
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/egltudckkmtk0u6v3e0b1pqb0a/9353025651.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=hill+climbing+racing+2+mod+apkPDF 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_off0000bf59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF59 10800 bytes
SHA-256: b6b64fa74b23492ee42e4a2a3fd58920984c8f897558100c37518ba8252cb57b
font_01_sfnt_off0000d7b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7B9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000efcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFCB 17200 bytes
SHA-256: e08685c56b7521f93b118333e82fe965e8e0955c0a12bfb086e64d9455153bdd