Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fb55ffae54b30ce…

MALICIOUS

PDF

77.7 KB Created: 2021-09-18 15:56:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: cb80c8e43ba75c20d70b6f02f910a59a SHA-1: 05d405820f636967e908a4d120440220de22e97c SHA-256: 4fb55ffae54b30ce36469dcc03c889acc7520ae77a7a0982b1f8db7dc1df24b7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm with numerous external URLs, many of which point to compromised websites or disposable domains, as indicated by the 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. No scripts were extracted, and the document body was unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://sial.pl/galeria/file/ziwilegorifetikukolez.pdf In PDF document text
    • https://jyapa.com/jhuoyue/uploadfiles/zegejir.pdfIn PDF document text
    • http://aatmicscience.org/asuserfiles/file/44105440623.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133ea42ecc48---64581724351.pdfIn PDF document text
    • http://yas-center.ru/userfiles/file/nubawedugutawetajiku.pdfIn PDF document text
    • http://ottomaniantextile.com/userfiles/file/vamas.pdfIn PDF document text
    • http://skkl.cn/filespath/files/20210905150522.pdfIn PDF document text
    • http://www.museopizarra.com/ckfinder/userfiles/files/58122682920.pdfIn PDF document text
    • http://mastervgtour.by/var/upload/file/raranedikefapu.pdfIn PDF document text
    • http://e-skala.pl/userfiles/file/dulumufodilemezexitefune.pdfIn PDF document text
    • https://xnkvinatimex.com/uploads/files/vojebilaba.pdfIn PDF document text
    • https://eobliecky.sk/userfiles/file/37478974296.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161403f275339e---41267075793.pdfIn PDF document text
    • https://safe-international.com/userfiles/file/80824896659.pdfIn PDF document text
    • http://vivo-mebel.ru/upload/file/pikosatisajojojogagi.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/16133b95fd8e41---gojakagebixevitene.pdfIn PDF document text
    • http://summitremodelinginc.com/userfiles/files/27930139935.pdfIn PDF document text
    • https://vargyasnekonyveles.hu/kepek/other/file/pofidodibizemuxozik.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/fotizibil.pdfIn PDF document text
    • http://baove247.org/upload/files/26540583240.pdfIn PDF document text
    • http://merrygoldholidays.com/ckfinder/userfiles/files/gubafikajorebaloka.pdfIn PDF document text
    • http://slbreakingnews.com/ckfinder/userfiles/files/geravuruzijawowareg.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=life+intermediate+b1%2B+teacher%27s+book+pdfPDF 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_off0000c358.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC358 19548 bytes
SHA-256: a8eb0e1902e028de894fc2eb69168214e453dfffebf6a48df0ec55d0524ad8a4
font_01_sfnt_off0000f78e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF78E 11112 bytes
SHA-256: 67c903d942caf8edc90af89312be51f8667011a5a7823b15d3ddf584e99c5112
font_02_sfnt_off00011129.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11129 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1