Malicious PDF — malware analysis report

Static analysis result for SHA-256 81adfb0144b0ada9…

MALICIOUS

PDF

78.4 KB Created: 2021-09-19 03:58:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c66ec16c7eb336cd45f0a0b5fecb0b5e SHA-1: 76fba7bee53c5ef6aac8007bae64b8b6427d62ad SHA-256: 81adfb0144b0ada9c25a11ad5c308928ce1edea665eb50a2b3ad120610126c8e
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is likely used to facilitate redirection to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://archism.ru/uplcv?utm_term=pattern+matching+algorithm+in+data+structure+pdf PDF link annotation
    • https://autoteam.in/ckfinder/userfiles/files/loluwizamojogeke.pdfIn PDF document text
    • http://spiregene.com/image/files/20210918_214347.pdfIn PDF document text
    • http://www.srijonihealinghome.com/fckimages/file/45225827083.pdfIn PDF document text
    • https://giasidaily.com/uploads/userfiles/file/62785618716.pdfIn PDF document text
    • http://taigesw.com/upload/files/pamuronubakujakuxas.pdfIn PDF document text
    • https://impulsa.mantareys.net/uploads/plantillas/files/babiladekuvafifano.pdfIn PDF document text
    • https://www.domaine-vrignaud.com/ckfinder/userfiles/files/10894053.pdfIn PDF document text
    • http://dongbanja.com/userData/ebizro_board/file/nijanetun.pdfIn PDF document text
    • https://iuoshili.com/upload/users/files/1623173264.pdfIn PDF document text
    • http://www.gpkoaee.ru/ckfinder/userfiles/files/53360103678.pdfIn PDF document text
    • http://carshopm.com/js/upload/files/75108829635.pdfIn PDF document text
    • http://rotarylaspalmas.org/documentos/file/17220486672.pdfIn PDF document text
    • http://otczenacts.com/media/files/2599921198.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/16136026b11221---8442305102.pdfIn PDF document text
    • http://t-p-fortune.com/userfiles/file/99932244408.pdfIn PDF document text
    • http://compagniaviaggi.gattinonimondodivacanze.it/themes/userfiles/files/gojesewuk.pdfIn PDF document text
    • http://kpdb.org/userfiles/files/varofekajudelod.pdfIn PDF document text
    • https://polaria.cz/images/file/vixidovikomuno.pdfIn PDF document text
    • http://lasantitosrestaurant.com/userfiles/file/84854933174.pdfIn PDF document text
    • http://dayou.tw/uploadpic/files/202109020530291617.pdfIn PDF document text
    • http://songhandiban.com/uploadfile/file/2021091611212773499.pdfIn PDF document text
    • https://aparcaderoshaddaichile.cl/uploads/images/files/zogidenareguresuxej.pdfIn PDF document text
    • http://bobmeetin.com/media/galleries/files/44546641527.pdfIn PDF document text
    • http://srtprogetti.eu/userfiles/files/95681300397.pdfIn PDF document text
    • http://leeandrewdavison.com/download/zisoxakujo.pdfIn PDF document text
    • http://punaide.com/userfiles/files/jolewigomuzemuse.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_off0000cab9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAB9 18060 bytes
SHA-256: f8eb6e5a6685bec717ecbc12d88f37745d4efe07a534a6f44933526a74916c19
font_01_sfnt_off0000f9c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9C4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000111db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111DB 11168 bytes
SHA-256: 7b49152951fae201a939712e98ef314abb972a01d398aab86dd70f614945e04c