Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3344d100b3e6878…

MALICIOUS

PDF

72.0 KB Created: 2021-09-20 01:14:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 77bbeb850c207b38395811296671290e SHA-1: b85d513f8932cd791fc4986a438e7eec9a8a3ada SHA-256: a3344d100b3e687876e90dc069219f6c70ec9d7953e77e670f3aba8d7bc0e47c
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent. The PDF also contains numerous external URIs, suggesting it acts as a link farm or phishing lure, likely to download further payloads or redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 https://sdhouse.info/ckfinder/userfiles/files/19645921891.pdf In PDF document text
    • http://www.masozilina.sk/ckfinder/userfiles/files/kofevop.pdfIn PDF document text
    • https://www.mtiwelding.co.uk/admin/ckfinder/userfiles/files/kugem.pdfIn PDF document text
    • http://studiomarazzi.eu/userfiles/files/5324158601.pdfIn PDF document text
    • http://tsutae-f.com/js/upload/files/fedodamaxivimekaridedef.pdfIn PDF document text
    • https://tutorsbureau.net/userfiles/file/mexebibibanetedobosuzefa.pdfIn PDF document text
    • http://ajk-opakowania.eu/upload/fck/file/58001076397.pdfIn PDF document text
    • http://infracsap.hu/files/file/67730272064.pdfIn PDF document text
    • http://praguetransfer.com/files/file/libaxut.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16131f75075071---65111367788.pdfIn PDF document text
    • http://k-sta.kr/FileData/ckfinder/files/20210901_6905DBEB2FC6DF5D.pdfIn PDF document text
    • http://aow.infogestnet.it/ckfinder/userfiles/files/lopererogonidesuxodufope.pdfIn PDF document text
    • http://supermarketdv.ru/files/file/posugeba.pdfIn PDF document text
    • http://kayapaliinsaat.net/file/jovevewugub.pdfIn PDF document text
    • https://superlitefan.com/uploads/files/jabiripabovopin.pdfIn PDF document text
    • http://restokrat.info/userfiles/file/zivalasibinirokadavakawo.pdfIn PDF document text
    • http://rallyteamwalraven.nl/file/wumepuj.pdfIn PDF document text
    • http://felixefontesadvogados.com.br/ckfinder/userfiles/files/98482846601.pdfIn PDF document text
    • http://santabruna.cl/upload/file/71643243292.pdfIn PDF document text
    • http://lerucherdesanges.fr/userfiles/file/54272267179.pdfIn PDF document text
    • http://archi1919.com/smlclub-files/file/duxoselobibasubipodijegub.pdfIn PDF document text
    • http://abwingssuffolk2.com/uploads/files/vojeza.pdfIn PDF document text
    • http://sp2wronki.pl/fotki/fotki/file/61994042509.pdfIn PDF document text
    • http://hiniceshine.com/upload/paxotel.pdfIn PDF document text
    • http://wabasnb.com/files/fckeditor/file/6173688106147b6266e34c.pdfIn PDF document text
    • https://101doctor.com/uploads/ckfiles/files/6139f6892f117.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=firestick+install+unknown+appsPDF 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_off0000b80c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB80C 10620 bytes
SHA-256: 5a23d70873cc2ca24c925bd3827c5f512f2b89af24e025487c53cf1bba4ffe91
font_01_sfnt_off0000d08d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD08D 16292 bytes
SHA-256: 2f2f0c54b55e48b2c73a864b56df11052f183445cf5840dd1658eecb22952d74
font_02_sfnt_off0000fa6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA6B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1