Malicious PDF — malware analysis report

Static analysis result for SHA-256 43bdca64c1676937…

MALICIOUS

PDF

82.0 KB Created: 2021-09-12 08:47:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d1b40696f589acf2f81a67e73e78ad64 SHA-1: 81cb82dc2be9027e6e10d0754b1a0ce15a503b68 SHA-256: 43bdca64c16769370363f703898eac98d47ffef9834c6f789a10c864cb260e3e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Analysis revealed it functions as a link farm, containing a large number of external URLs pointing to various domains, many of which are likely disposable or used for redirection. This suggests the primary purpose is to lure users into clicking malicious links, potentially leading to credential theft or further malware infection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://queure.ru/uplcv?utm_term=psd+to+xml+android PDF link annotation
    • https://hoangphatdanang.com/uploads/image/files/33846011598.pdfIn PDF document text
    • https://bedandbreakfastchia.it/userfiles/file/lizifalomajuwidaxifaze.pdfIn PDF document text
    • http://gospel-pour-100-voix.com/fichiers/newsletter/file/biwaf.pdfIn PDF document text
    • http://haki.vn/uploads/files/tifafigopugewu.pdfIn PDF document text
    • http://rent2day.ca/ci2/userfiles/files/95536796583.pdfIn PDF document text
    • https://limadelimon.com/images/file/89553358064.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/9p4r4qpo1jc1ngeh0bikfltlc5/wusex.pdfIn PDF document text
    • https://sadex.pl/fck/file/23831764722.pdfIn PDF document text
    • http://bfcy88.com/uploads/files/donemaj.pdfIn PDF document text
    • https://olgunbey.com/upload/ckfinder/files/kekopimu.pdfIn PDF document text
    • https://doctmcooper.com/userfiles/files/13808824573.pdfIn PDF document text
    • https://studiecarriere.it/uploads/file/86085459404.pdfIn PDF document text
    • https://mar3ol.com/Files/files/kevaxofov.pdfIn PDF document text
    • http://harckocsik.hu/userfiles/file/83303967542.pdfIn PDF document text
    • http://nsmpublicschool.org/slbdavbatala/userfiles/file/98159620302.pdfIn PDF document text
    • http://c-amc.com/upload/files/dejal.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613d7ddeaedce---nozasoxogugoze.pdfIn PDF document text
    • http://mebelhotel.ru/userfiles/files/45756516496.pdfIn PDF document text
    • http://gallery4walls.com/upload/editer/file/84254334089.pdfIn PDF document text
    • https://lawrenceyezersky.com/userfiles/file/xafifosarubafunisul.pdfIn PDF document text
    • http://amicissiapiemonteisa.it/userfiles/files/fukalukuviposikuxo.pdfIn PDF document text
    • http://ap116.ru/userfiles/file/41461258174.pdfIn PDF document text
    • http://holidayinntorino.com/userfiles/files/6384723556.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_off0000dc29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC29 17688 bytes
SHA-256: 331f6ee01c66aecf659f71c6396e67fa3a69ff54b902964e91546fce1e1fcc6d
font_01_sfnt_off00010ab2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AB2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000122c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122C9 10380 bytes
SHA-256: 52dd9a2fb8f2b04f059f67bf0e3f661500e34f44c0d5b0096d329f1645b28bf2