Malicious PDF — malware analysis report

Static analysis result for SHA-256 9999bf55887d708d…

MALICIOUS

PDF

85.2 KB Created: 2021-09-08 04:25:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3cb652ba8e777fadbbb18b5244c02ff2 SHA-1: 629d18bc2e4be10f251a5f094e0a88b85974dfdd SHA-256: 9999bf55887d708deb1a2b0abd400a62373fbc7e6391ad6dc12a6c9cfe6c543e
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. The document body is heavily obfuscated and unreadable, providing no direct user-facing lure.

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 http://ifaistos.reality.gr/~triantaf/images/file/38516259363.pdf In PDF document text
    • http://bukharajohnscreek.com/sites/default/files/file/wozemudenarakejidoju.pdfIn PDF document text
    • https://jgmurphy.com/wp-content/plugins/super-forms/uploads/php/files/f782bb20d52d497cd10db3c4edc8387e/bugivejureru.pdfIn PDF document text
    • http://hopkins1983.com/clients/861771/File/foroxi.pdfIn PDF document text
    • https://maydangson.com/vietkiendo/upload/file/19456776811.pdfIn PDF document text
    • http://cherryontop.pl/upload/fotki/file/98892524697.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16082eb4524663---visevonikebinexa.pdfIn PDF document text
    • http://anhuizhkj.com/upload_fck/file/2021-8-22/20210822171407175507.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610c087a2cfbd---miposanenugijimebuba.pdfIn PDF document text
    • http://levne-pohary.cz/UserFiles/File/81421495606.pdfIn PDF document text
    • https://rugsinc.in/UserFiles/files/wiwalujulosifuk.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/ac0c2fc141aa72dbb6be87ded2e9ab8e/puridad.pdfIn PDF document text
    • http://pmrs.ps/userfiles/file/nulipajala.pdfIn PDF document text
    • https://33mobility.net/uploads/files/vukovazulemagedesex.pdfIn PDF document text
    • https://www.potravinyav21.cz/ckfinder/userfiles/files/jididojewimura.pdfIn PDF document text
    • http://avvocato-callegaro.it/public/file/temipajos.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609a4177bb935---77752771397.pdfIn PDF document text
    • https://www.hkha.org/ckfinder/userfiles/files/sosufur.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/f37ae58c9fd025fb6c8d5a83d1014a8d/mupitimojesitijobufak.pdfIn PDF document text
    • https://phr4u.com/files/28754064291.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160711c02ccecc---43252723927.pdfIn PDF document text
    • http://alpha-cp.com/userfiles/file/jususawozezenenojigulen.pdfIn PDF document text
    • https://manuscripthandler.com/userfiles/file/74054385989.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=ssc+cgl+2018+tier+1+syllabus+pdf+downloadPDF 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_off0000e263.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE263 18692 bytes
SHA-256: fff19fb4ba4f0afc38b5eef0a75442ef030d812b70fdb7b9f0b37230bb713ec8
font_01_sfnt_off00011341.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11341 11812 bytes
SHA-256: 8aca006de2886a008019112d6273a187835667d2cf9f4ea7e1a65024b232d5ee
font_02_sfnt_off00012f5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F5F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1