Malicious PDF — malware analysis report

Static analysis result for SHA-256 4681821e5af7edaf…

MALICIOUS

PDF

88.3 KB Created: 2021-09-09 04:49:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 910d72df1f8cc3751657cb6ee9b0e42b SHA-1: ceece395e291780b649c7f6581dc377a888c4c91 SHA-256: 4681821e5af7edafa06fe644a5ec62df23e4cba6708ca08d4ffc7e9e3936c98b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF contains numerous external URIs, many pointing to disposable hosting, suggesting a link farm or phishing lure. While no scripts were explicitly extracted, the PDF structure and the presence of external links strongly suggest it is used to redirect users to malicious sites, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://healthmatters.me/userfiles/file/pozezedo.pdf In PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1613676cd6d7b4---70373669817.pdfIn PDF document text
    • https://www.marjojaspers.nl/ckfinder/userfiles/files/31414912602.pdfIn PDF document text
    • https://tapetcenter.ro/app/webroot/files/userfiles/files/julexifux.pdfIn PDF document text
    • http://lionsmarsala.it/userfiles/files/47901381377.pdfIn PDF document text
    • https://elitstroycraft.ru/source/file/bajetosa.pdfIn PDF document text
    • https://vas-vill.hu/userfiles/file/komimopetosukareruliv.pdfIn PDF document text
    • http://kor-ra.ru/UserFiles/file/2207648821.pdfIn PDF document text
    • http://interno-kazan.ru/upload/files/6533511547.pdfIn PDF document text
    • https://lufty.cz/UserFiles/files/niwavurafaloj.pdfIn PDF document text
    • http://zhongyuemedia.com/filespath/files/20210902052117.pdfIn PDF document text
    • http://clairerolo.com/userfiles/file/jususexep.pdfIn PDF document text
    • http://eltdb.com/UserFiles/files/sidewilezekimopureb.pdfIn PDF document text
    • https://pgprojekt.pl/Upload/file/34334879267.pdfIn PDF document text
    • https://toyotaautobody.com/ckfinder/userfiles/files/62236214549.pdfIn PDF document text
    • http://cellesekorea.com/ckupload/files/87342269853.pdfIn PDF document text
    • http://jatechkj.pl/upload/fck/file/vinadodorewiwakigoda.pdfIn PDF document text
    • https://cakenflowersonline.com/userfiles/file/49672408649.pdfIn PDF document text
    • http://polyacer-ecp.com/userfiles/files/20210908_043027.pdfIn PDF document text
    • https://horacebatten.com/ckfinder/userfiles/files/fanitijetegoranu.pdfIn PDF document text
    • https://sdhouse.info/ckfinder/userfiles/files/3232136933.pdfIn PDF document text
    • http://lactopad.com/uploads/files/deved.pdfIn PDF document text
    • https://globaldreamindia.com/webcms/file/31305276.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/savixexer.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=justin+bieber+ft+ed+sheeran+lyricsPDF 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_off0000ec50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC50 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010467.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10467 10800 bytes
SHA-256: b5c23d63151ba569f40d950b486970b4882af4aad6e19332b40f62beff9bba87
font_02_sfnt_off00011d45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D45 20556 bytes
SHA-256: c3cf6a6ed4f16cd5cf451775a69ea35b46ba05c55690944a3480e9fab46993a9