Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef27ffecebc34abc…

MALICIOUS

PDF

84.9 KB Created: 2021-07-01 21:36:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d906d7cc92c55da911fdbd725e3b5dde SHA-1: f94f01fabc4d68baf12a8ec9d77e1eae34bff42d SHA-256: ef27ffecebc34abc6f83d823d805b83f59f796c1073408baa1278a67263cfd4a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS upload directories. The presence of external URIs and link farms suggests the document is designed to redirect users to malicious sites, likely for phishing or to download further payloads. No scripts were extracted, but the PDF structure itself is used to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://chcial.ru/uplcv?utm_term=jingle+bells+piano+chords+easy
    • https://bwawarszawa.pl/upload/file/vojonalekaxanakog.pdf
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/368f7e96c7437fd4ae2b313d21bb37b1/ravolefafab.pdf
    • https://cgeminfos.ma/upload/file/tabemerimisavikofugiwo.pdf
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/16081817dbc01b---45086239520.pdf
    • https://cncostruzioni.com/userfiles/file/korixefijukax.pdf
    • http://shuswapladystriders.ca/userfiles/file/furirasobovesoxasite.pdf
    • https://anmoul.com/userfiles/file/55590687247.pdf
    • http://k1a.ru/images/files/file/2476955249.pdf
    • https://amatnieks.com/pictures/image/20180304220.pdf
    • http://aarogyamedico.com/userfiles/file/lixepupesavo.pdf
    • http://tgtech-auto.com/userfiles/file/tageponifudilomeleb.pdf
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160cb2f5118c63---75000995970.pdf
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16078661ac3be5---25370085388.pdf
    • https://ekransamara.ru/files/21702255238.pdf
    • https://investmentskillsgroup.com/images/userfiles/file/fatixabe.pdf
    • https://dbjadow.pl/attachments/file/44469978034.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa0d51b6506---ludejeb.pdf
    • http://www.siscbolivia.com/admin/uploaded/fck/file/fuwavozebusorekiwolunuvo.pdf
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080729df2409---42878181226.pdf
    • http://vytvarnyobchod.cz/UserFiles/File/5659413726.pdf
    • http://makesomenoise.hu/upload/file/jivunuwezulakipewixo.pdf
    • https://sip7.pl/autoinstalator/sip7.online/wp-content/plugins/super-forms/uploads/php/files/39cbc3e4ebf70e2f9ab9423c7375f72c/gozofoxidijo.pdf
    • http://thallo-food.hu/uploads/ckfinder/userfiles/files/21609828489.pdf
    • http://willbramephotography.com/87802280422.pdf
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160841243bf1bf---bazapof.pdf
    • 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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e798.bin
ac8a99aa28ddf6aafd2f960a7faf67eed4cabd067e5c018332ac0b7a49e69155
pdf-font-stream PDF embedded font (sfnt) at offset 0xE798 10940 bytes
font_01_sfnt_off00010074.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10074 16792 bytes
font_02_sfnt_off00011886.bin
65feaebbb4ee2a56bcdd4fdf7a134de00fe80cf568beaecd3c32ef2aea055bfb
pdf-font-stream PDF embedded font (sfnt) at offset 0x11886 17588 bytes