Malicious PDF — malware analysis report

Static analysis result for SHA-256 fdcd5420096a8477…

MALICIOUS

PDF

69.1 KB Created: 2021-09-19 07:38:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 863d54aa382776512779a35bde050891 SHA-1: 584ac005c39dc14c09a6f2d63c540bddd9f2e6a1 SHA-256: fdcd5420096a8477e63499e73a14d27644eb2ca6a9fde4a486da630b626e89f0
174 Risk Score

Malware Insights

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

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript and multiple links to external PDF files hosted on various domains, some of which are identified as disposable hosting. The heuristic 'PDF_RANDOM_URL_LINK' specifically points to a suspicious URL, indicating an attempt to redirect the user to potentially malicious content. The presence of embedded JavaScript suggests an attempt to execute code, likely to facilitate the download or execution of further stages of the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 http://barrospizzadb.com/uploads/files/90507208017.pdf In PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161417e6cbd324---5986349664.pdfIn PDF document text
    • http://gaia-onlus.org/userfiles/file/vasisamez.pdfIn PDF document text
    • http://morethancars.nl/uploads/edytor/file/jebut.pdfIn PDF document text
    • http://ptsound.com/plugins/ckfinder/userfiles/files/lumeburafopibuvi.pdfIn PDF document text
    • http://lapenya.cat/imgjovesnaves/file/luramutipinowepub.pdfIn PDF document text
    • https://horgaszvelem.hu/ckfinder/userfiles/files/kuperasujam.pdfIn PDF document text
    • https://classconnbio.com/img-jacson/files/gapipizefigajarelawofob.pdfIn PDF document text
    • http://ambulatorioveterinarioilghirlandaio.it/userfiles/files/31320835481.pdfIn PDF document text
    • http://logenamerica.com/userfiles/file/76090955994.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/76861908654.pdfIn PDF document text
    • https://www.hkfew.org.hk/ckfinder/userfiles/files/jekud.pdfIn PDF document text
    • https://nordavril.com/userfiles/file/66754848358.pdfIn PDF document text
    • https://poolpoint.be/uploads/file/lugisuratidazeboj.pdfIn PDF document text
    • https://my-natural-style.net/upload/files/gigijunezonag.pdfIn PDF document text
    • http://mizuho-co.net/file/ck/files/85781519169.pdfIn PDF document text
    • http://archi1919.com/smlclub-files/file/serivadabamunemisisezedir.pdfIn PDF document text
    • http://maymaygiaydachidang.com/upload/files/43658689583.pdfIn PDF document text
    • http://to-kajihan.net/js/upload/files/87584634961.pdfIn PDF document text
    • https://pmsp-me.com/userfiles/files/38217563650.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/i9g0dv7ojed9k635mi3fkqdtt5/fapefokafetun.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=non+sporting+breedsPDF 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_off0000b130.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB130 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c947.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC947 10476 bytes
SHA-256: 5bd24beb2309ec6481dedf019d853c18fe43b322601e47e5e08db45f532b571d
font_02_sfnt_off0000e0bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0BF 15276 bytes
SHA-256: aa3097f38a69d44d6407f2c072e6622c2a8047174b6cfc35249e53d206a1cbf4