Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff61b0e80b92b5d3…

MALICIOUS

PDF

86.9 KB Created: 2021-07-03 11:45:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: b56cd1ef6154ce26556845e223d4d17e SHA-1: 307a314e0eef6e8378feeae3e1b727aed41ed294 SHA-256: ff61b0e80b92b5d364b356d5cff9a085a21079d76243aa09af9266db4cd66012
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress upload directories and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics reveal.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://thankschicken.com/uploads/files/12433580593.pdf In PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d36c4cc4812---wurid.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c2314018f33---87027134224.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/854fb16061ec21a52cda9dee5a242879/85305156465.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/43745944476.pdfIn PDF document text
    • http://cukiernia-waltar.pl/qcms/userfiles/file/begasugim.pdfIn PDF document text
    • https://rubin2000-distribuitorshop.ro/userfiles/file/daziteniworudotewazare.pdfIn PDF document text
    • http://xn--9p4b29dncp2cc6y.net/upload/fckeditor/file/25647978114.pdfIn PDF document text
    • https://allcreaturesinc.com/files/files/vawuturoveputo.pdfIn PDF document text
    • https://www.makathastaliklari.net/wp-content/plugins/formcraft/file-upload/server/content/files/16081a0172e790---texulanakusetixaxov.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3cb0e19c56---serururu.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/702d2490c2517507947efdad1c7c0ceb/35282631312.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608350a840e6c---40675576942.pdfIn PDF document text
    • http://furniture83.com/upload/files/timego.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/cfc981bf98186908d9481fc9bafe3f7a/68595163099.pdfIn PDF document text
    • https://noddy.nu/images/file/33976029422.pdfIn PDF document text
    • https://equantumconsulting.com/files/files/17151506104.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1ae107cf19---zutaxetog.pdfIn PDF document text
    • https://felix-schulze.biz/wp-content/plugins/super-forms/uploads/php/files/fgsgrer91qove5qs1aq072kjko/93926724716.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/57m0e9d1tek7bn7ni0pa9kq7ud/kimep.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a90891c2f8d---30863973803.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/oosmnf66feqo2ll57len3309ao/jovaro.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1609a53fecb58f---piwos.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fdcc86c381---verimusiwebamapotofodazuf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=how+to+check+if+a+game+is+downloading+on+ps4PDF 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_off0000ef17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF17 11212 bytes
SHA-256: e871984bc8f0eebf8df47220deab0b793438eb98c8040364566a4917d84aa237
font_01_sfnt_off00010904.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10904 17432 bytes
SHA-256: af8e6ca3f44c98a15bbb49be8966b4b92b182c74312f314b186476fedc430bef
font_02_sfnt_off000135fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1