Malicious PDF — malware analysis report

Static analysis result for SHA-256 3dd1553fa2eb1177…

MALICIOUS

PDF

75.1 KB Created: 2021-09-21 11:11:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 46b7bdf8fc85c1424907e11ba3ec9a0c SHA-1: 43e9a59309c6865ec02fa53f0692cb8c6ff91d1b SHA-256: 3dd1553fa2eb1177676b7140a8511fc88331b589b1a28922ffffa39738dcc31a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, suggesting an attempt to redirect users to malicious sites. The document body is heavily obfuscated, but the presence of external URIs and the link farm heuristic strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://archism.ru/uplcv?utm_term=what+happens+when+you+do+a+factory+reset+on+your+android+phone PDF link annotation
    • http://nationalherbo.com/userfiles/file/41535467985.pdfIn PDF document text
    • https://rosanaalvarracin.com/userfiles/file/nevefisaguvo.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/hm8jhrsgtj4m6esefihs5ktgov/xepuzoj.pdfIn PDF document text
    • https://vayamcs.com/content_files/files/26769114544.pdfIn PDF document text
    • http://utcsp2.rustyramone.com/uploads/files/967607033.pdfIn PDF document text
    • https://tgvl.in/uploads/fck/files/14368863862.pdfIn PDF document text
    • http://chongthamnguoc.vn/img/files/44162406530.pdfIn PDF document text
    • http://hoadondientu-ptp.vn/images/ckeditor/files/lanajiz.pdfIn PDF document text
    • https://oazapiekna.com/zdjecia/fck/file/fopunixudama.pdfIn PDF document text
    • http://kulturazebrak.cz/userfiles/dopizaxi.pdfIn PDF document text
    • http://parbatsamajjapan.com/img/files/files/87123030804.pdfIn PDF document text
    • https://mamotato.ro/userfiles/file/3188117870.pdfIn PDF document text
    • https://g55net.com/webpagebuilder/ckfinder/userfiles/files/94585940283.pdfIn PDF document text
    • http://888spirits.com/userfiles/file/10354474251.pdfIn PDF document text
    • http://bayanairag.com/uploads/userfiles/files/puzokiwivezogow.pdfIn PDF document text
    • http://wingmanplanningdemo.com/userfiles/files/nuzovudivovubi.pdfIn PDF document text
    • https://jasmijnbloemengroen.nl/userfiles/file/93584904056.pdfIn PDF document text
    • http://kor-ra.ru/UserFiles/file/balevuzojetepepofeg.pdfIn PDF document text
    • http://taispacedesign.com/upload/files/43727042088.pdfIn PDF document text
    • http://talleresjpg.es/img/file/fojolaxewex.pdfIn PDF document text
    • https://lanhcongnghiepthinhphat.com/upload/files/xifadusavekazesefowun.pdfIn PDF document text
    • http://wsmr.us/userfiles/file/4375920732.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16137fab52e950---99372435026.pdfIn PDF document text
    • 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_off0000c0b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0B7 10964 bytes
SHA-256: 685de618b55c86cb680927f10d6b3491cddb032ceae1d394e36663cb21ec0404
font_01_sfnt_off0000da31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA31 16960 bytes
SHA-256: 3e0c36b616a61bfdaa5d4fa95c24bc684cfb8aa18410fdf95adeba341d877fbd
font_02_sfnt_off00010618.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10618 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1