Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4abd5e39d1d3cc5…

MALICIOUS

PDF

87.8 KB Created: 2021-07-22 14:26:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: d73c6e734b3fec51ea85bdf744e87df6 SHA-1: 150aaa426ca366614a21e0b09b6e663a92181bf2 SHA-256: f4abd5e39d1d3cc53ea50dbf49c26b2dac3928eeabf69302770adb7b420c515c
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, which in turn host other PDF files. This structure suggests a link farm designed to obscure the ultimate destination, likely a phishing page or malware download. ClamAV and ML classifiers strongly indicate malicious intent, with the PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirming the use of disposable hosting for link distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a291346d03d---zumafod.pdf In PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/5c4b82379a6690c1f5d2c8aacebaf683/xemumitixoser.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/144c214b07dc72151c73dc69b674e426/18165801305.pdfIn PDF document text
    • https://dietacud.eu/upload/file/jitilikobebu.pdfIn PDF document text
    • https://muratay.nl/userfiles/file/84481627010.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084c9db31e4f---76932274263.pdfIn PDF document text
    • http://dgjinhak.kr/DATA/upload/files/202106300756369836.pdfIn PDF document text
    • http://irk-yoga.ru/upload/files/39943437672.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/2bd70a255cf054e45f080c8313c8d8b9/96568102198.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c990eeaaf44---68920621777.pdfIn PDF document text
    • http://nedirajtebosnu.net/userfiles/file/18569854078.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607351c1cb3d8---15999013459.pdfIn PDF document text
    • http://avvocatoandreabruschi.it/userfiles/files/kubijoli.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/admktvc5p7ebibdl997cvko7j6/sominuxu.pdfIn PDF document text
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/3790d09c598bbad5da50401115095bda/wabuduwidix.pdfIn PDF document text
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/a148225c9c9bdf0297211dfa0c5fec8b/fiwuvawakokebafisewi.pdfIn PDF document text
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ebc6839a97bb69b9fad014835b3928aa/xalezulebe.pdfIn PDF document text
    • http://hhcreunion.com/clients/4/43/43f38dc94a4d709fe78decf5bd9d7370/File/pojimefidivenobazanoli.pdfIn PDF document text
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c851d06499b---wokitulabawotarazakozibu.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b7a20e0ed7---60911141118.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607773a9cf4b3---kozesegovunen.pdfIn PDF document text
    • http://bulk-supplies.com/userfiles/file/lojewazotojesuj.pdfIn PDF document text
    • https://dnmpaint.com/sdcc/images/file/86552042979.pdfIn PDF document text
    • http://citadelcaralarms.com/userfiles/file/vibavakunewofofofowoxe.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160abf59165823---gizezebaligomubapix.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=new+electric+slide+songPDF 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_off0000f4e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4E1 10444 bytes
SHA-256: 141a7ab1c934fd178500167747256ea24cba5e776d6ccad211c3bb36f7305e76
font_01_sfnt_off00010c86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C86 17364 bytes
SHA-256: c6e6c4acd122d5a831a44908e2301ddc727bcee06c7d42ae1d8926e6e592afa6
font_02_sfnt_off00013967.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13967 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1