Malicious PDF — malware analysis report

Static analysis result for SHA-256 da12b389eb33c2c8…

MALICIOUS

PDF

72.0 KB Created: 2021-05-29 11:21:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 7ccf2edf9be2dfbee1971b8023417be9 SHA-1: 5853734a6ee22676938889fbb56a1170b7da5a5a SHA-256: da12b389eb33c2c8c440c2ce8cc0f8f7c2fa0c12c2ea7ba671c0975225c26d46
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, pointing to multiple compromised WordPress upload directories and disposable hosting sites, suggesting an attempt to distribute further malicious content or engage in SEO abuse. The embedded URLs and the nature of the heuristics strongly suggest this file is part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://fullcolorspandoeken.nl/userfiles/file/5049682761.pdf
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b8342eb05c---jatet.pdf
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609ed011d64f8---86177752551.pdf
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1488f18308---zixorujukogixifa.pdf
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608c3c637a31d---80582428337.pdf
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa88241631f---43944011447.pdf
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/cch6hdtlusni2apeggi8s2e7f0/vuzoxexufumanenikug.pdf
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a9685328198---dirupasiwaxusufikus.pdf
    • http://shreejians.com/userfiles/file/80589077999.pdf
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d7e1b3a4e8---71807085439.pdf
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d9487444f1---nanapikerulupobefepujof.pdf
    • http://www.alquilerbares.com.ar/wp-content/plugins/formcraft/file-upload/server/content/files/16083bbb8530db---dawurobedagupitu.pdf
    • https://upchealth.net/wp-content/plugins/super-forms/uploads/php/files/695be8d7033b84e78a89130848303430/xamejapigarovaw.pdf
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1608bebd91ec49---pakabinofal.pdf
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/1606effaf5aa05---sofozo.pdf
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607e45a7962b7---setajukuzozogakogexum.pdf
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/b0c6deec749a7fb3daf124adc6d99d16/22874678984.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=calcular+el+peso+molecular+de+nh3
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d859.bin
37f68a18ffce37faf81a31c650473f7f95e932b4f4e464e42f7adfe361da514b
pdf-font-stream PDF embedded font (sfnt) at offset 0xD859 5380 bytes
font_01_sfnt_off0000ea71.bin
b0a594b09140d13979131c6a24d389591a5a3ddebe0facdcd7bb7bccdde0ffd6
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA71 12640 bytes