Malicious PDF — malware analysis report

Static analysis result for SHA-256 551a7a3095bc571d…

MALICIOUS

PDF

72.5 KB Created: 2021-04-29 04:11:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 0fae94d5a1d0b252839d190cdd6cc329 SHA-1: decea113564e9e269b10296b7944fd6e50af4b42 SHA-256: 551a7a3095bc571d1411c2b818ed2220c8fd62d14289d60a67e72eecb7bf0cf3
216 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to compromised WordPress upload directories, suggesting it's part of a link farm designed to distribute further malicious content. The document body, though heavily obfuscated, contains metadata related to wkhtmltopdf and a date, but no clear textual lure. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics strongly indicates a malicious intent to host and distribute payloads via these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Recovery secret / private key request critical SE_SECRET_RECOVERY_LURE
    Document requests recovery phrases, private keys, backup codes, or saved passwords. Requests for these secrets in a document are high-risk.
  • 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://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb3855b990---wabujenuw.pdf In PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/47f44f6fe44b05d68e98150b33a04936/natulinunogekokuraji.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9ad9d65de---xuzatu.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16071f3414eafd---fesirabisasudiridufemifar.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089cf60bb2f6---99811628165.pdfIn PDF document text
    • http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e3412057dd---bozujugesabenad.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160703cc9f04dd---5654356300.pdfIn PDF document text
    • https://ajitcoatings.com/uploads/tisadexulemapulazev.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/dd1c1a73f5a1bddc4ceb4cf6d6369a1b/saxuxon.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/5736ec27449b9cc623975ce277913da3/seloxomakepufovitoxej.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d95b5c32bf---32387295727.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/87ee35127dea6e1f3a97042789f8d019/66046444678.pdfIn PDF document text
    • https://www.themeshcowork.com/wp-content/plugins/super-forms/uploads/php/files/f1340328c49bc8cb4b990414a4d9baa0/50700920616.pdfIn PDF document text
    • https://realestateconnect.us/wp-content/plugins/super-forms/uploads/php/files/s1annd7kqafukol3c52flfv0u6/8951941219.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/bq05u63ookhpm6dj1c48e88k02/16872943802.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/7cdc0e8fbe4c17316793f7528292c080/59374356607.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160746b0cdfa3c---tixijezotituxejezisugix.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8f835a7ba---93967490556.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=champ+bengali+movie+english+subtitlesPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e070.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE070 5244 bytes
SHA-256: 640c4463905f8b1e1ad91e099fea31a2a35847b837bd906b09454da56833b60c
font_01_sfnt_off0000f221.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF221 10264 bytes
SHA-256: e620dd5d7dcb2af6d0ba0d44c2ecd4fd42486cd2158dece08491561aa110f3d2

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