Malicious PDF — malware analysis report

Static analysis result for SHA-256 e1f5cdcb6c1dce03…

MALICIOUS

PDF

77.9 KB Created: 2021-09-09 09:49:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 05528c3b6e14523852f234c190b96057 SHA-1: f5c6cfcb5a32237a17fb1862eddb65a9b467e57b SHA-256: e1f5cdcb6c1dce0316fbd69f936e72882967c93f11b29f8696007df9440d97df
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on various domains, indicating a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this is a tactic to obscure malicious intent or distribute further payloads. The ML classifier and ClamAV detection confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://ozanatalan.com/iboard/includes/userfiles/files/32739144992.pdf In PDF document text
    • http://kryotherapie.net/neu/userfiles/file/pevijikojeduvumexu.pdfIn PDF document text
    • http://kawana.tech/userfiles/file/ginujagovenef.pdfIn PDF document text
    • http://hooleihomes.com/cms_images/file/65614174821.pdfIn PDF document text
    • http://sherwoodchambergolf.com/ckfinder/userfiles/files/18317122184.pdfIn PDF document text
    • http://offerseir.com/basefile/offerseircom/files/2952718990.pdfIn PDF document text
    • https://hobbypet.cz/files/file/90629601994.pdfIn PDF document text
    • http://delfosventures.eu/userfiles/files/jigovanufimepubisiwan.pdfIn PDF document text
    • https://fo-prefectures.com/pages/files/28255492154.pdfIn PDF document text
    • http://siripanyalamphun.com/user_img/files/75852996949.pdfIn PDF document text
    • https://stpm-sa.com/userfiles/file/pipufovelebopefedemuwet.pdfIn PDF document text
    • https://ourguarantees.com/userfiles/file/zabamagisu.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/161307b504eabb---munotifip.pdfIn PDF document text
    • https://arbormaster.net/uploads/files/69152598759.pdfIn PDF document text
    • http://emachn.com/data/attachment/file/87070913037.pdfIn PDF document text
    • http://kkagro.com/media/images/upload/file/56528257946.pdfIn PDF document text
    • http://adhdesign.de/userContent/files/20210909030836-7693639782.pdfIn PDF document text
    • https://www.pension-chevaux-haras-gabereau.fr/ckfinder/userfiles/files/gudoxojif.pdfIn PDF document text
    • http://www.tomasjelinek.com/img/pub/file/sulorewewajazegugixixib.pdfIn PDF document text
    • http://ud2-140.com/files/lizikavewigap.pdfIn PDF document text
    • http://energosol.pl/images_cms/file/40567238339.pdfIn PDF document text
    • https://www.bakkersvlaanderen.be/resources/plugins/ckfinder/userfiles/0/files/legan.pdfIn PDF document text
    • https://www.barrau-philippe-sedeco.fr/ckfinder/userfiles/files/mozajorizibadutipakajez.pdfIn PDF document text
    • http://www.sandipmallick.com/fckimages/file/ximelolalawopagojidaja.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=true+skate+apk+iphonePDF 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_off0000cdee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDEE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e600.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE600 17348 bytes
SHA-256: ca3f90724845de6dc8ae85849858fc9999d390596076b7222659a091d46996d8
font_02_sfnt_off000112be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112BE 10456 bytes
SHA-256: 149c16985298e7b41faff9ff7f480bbb0eef78e3da44d91881a21d69f5bb7598