Malicious PDF — malware analysis report

Static analysis result for SHA-256 8557ad3b63c41d4a…

MALICIOUS

PDF

102.5 KB Created: 2021-10-06 15:57:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: c3bec8c72127ae5e17acb008cc19cf48 SHA-1: 68dbcbca5f1fb940aadec14fa090b2d1c4850a9f SHA-256: 8557ad3b63c41d4ae8c7edee39b8f8d7fd77956cbff34b360637720c50eec4df
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to external websites, many of which are hosted on compromised WordPress sites or disposable domains. This pattern is commonly used for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://cructi.ru/uplcv?utm_term=scales+for+trumpet+pdf PDF link annotation
    • http://papinchess.ru/userfiles/file/wezejenuzogibine.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/feg4nt7ncskmldnhma1srpcfke/23145643761.pdfIn PDF document text
    • http://allergya.news-read.com/upload/files/larefap.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/1gjut9uja7qne3u77cfhq8h3aj/digemivuwodimifevugi.pdfIn PDF document text
    • http://chinajessie.com/seadata/data/uploads/img/file/163351076249.pdfIn PDF document text
    • http://gardena.crazyrockinsushi.com/uploads/files/balilojitamofadokepon.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/entd0iagohd7rcbo68p0q3k1fj/51145885229.pdfIn PDF document text
    • http://tk-weld.com/images/library/File/lisorilegir.pdfIn PDF document text
    • http://dolphinkorea.com/files/files/dupexapiwizizezi.pdfIn PDF document text
    • http://gerastar.com/userfiles/file/gakekaripetovi.pdfIn PDF document text
    • http://rotterdampools.com/contents/files/nopotediki.pdfIn PDF document text
    • http://bouwbedrijfbouwheer.nl/userfiles/file/tobetirupogimepekimurawur.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615d5c8f8d795---88621055313.pdfIn PDF document text
    • https://pianotuningdarwin.com/userfiles/files/jawewejafireni.pdfIn PDF document text
    • http://4reality.cz/userfiles/files/38410085740.pdfIn PDF document text
    • http://tageedesign.com/ssmpt/documents/file/77147631232.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16135494e3ed70---bewevegukuzagagevaveb.pdfIn PDF document text
    • http://verduciautodemolizioni.it/userfiles/file/puvixadivurosone.pdfIn PDF document text
    • https://vibangnhadat.com/uploads/files/51178267539.pdfIn PDF document text
    • http://mtt-association.fr/upload/file/dotigo.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132ae4b7a4e4---jupelibojabez.pdfIn PDF document text
    • http://kaies.cn/upfiles/2110011729305876673xi0ci.pdfIn PDF document text
    • 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_off0001221e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1221E 23084 bytes
SHA-256: 60826e8924feb1ea76e3dbaf5ff657703632bed20484ce25ac0d9e5d9de3affc
font_01_sfnt_off00015c25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15C25 10760 bytes
SHA-256: 240e3ce3f692a415e2c80313689bed25c41f6d118d2fbc2fab3e771ace9b6b6a
font_02_sfnt_off000174f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x174F6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1