Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c8872212177d16d…

MALICIOUS

PDF

80.2 KB Created: 2021-09-17 05:58:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: cd123458876c288ba9b417ede9c4c67e SHA-1: 21425d7d3be8a147bc95e2814e660c57f2235fc4 SHA-256: 3c8872212177d16d64312604a6db1033e0fd1175f451a6c307194714205a4c80
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links to external websites, with several heuristics indicating a link farm and algorithmically generated URLs. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the PDF structure itself is used to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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
  • 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.
  • 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://cuoredicane.it/userfiles/files/retofitunotuloj.pdf In PDF document text
    • http://zxpgw.com/userfiles/file/jutirom.pdfIn PDF document text
    • https://uzmanwebci.com/calisma2/files/uploads/tanumabodixuxalog.pdfIn PDF document text
    • https://alpinismbihor.ro/app/webroot/files/userfiles/files/47443996448.pdfIn PDF document text
    • http://cokhiminhhien.com/media/ftp/file/lokigorosopusapep.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/xaromazilixuretosusufodol.pdfIn PDF document text
    • http://sprinter-lab.ru/content/File/41908041915.pdfIn PDF document text
    • https://cowik.pl/upload/10659893569.pdfIn PDF document text
    • http://rhondachem.com/d/files/54247168372.pdfIn PDF document text
    • https://hanurichurch.org/ckfinder/userfiles/files/lupar.pdfIn PDF document text
    • https://hotelristorantenovecento.it/wp-content/plugins/super-forms/uploads/php/files/65f05190a5dd0756235e17ff04819b08/1295931631.pdfIn PDF document text
    • http://tipiland.net/upload/file/89647903419.pdfIn PDF document text
    • https://somogyplusz.hu/files/54795216879.pdfIn PDF document text
    • http://sbcnepal.com/images/file/2573774482.pdfIn PDF document text
    • http://ambulatorioveterinariovianello.eu/userfiles/files/69312518507.pdfIn PDF document text
    • http://www.almansori-ye.com/almansorifiles/files/namadox.pdfIn PDF document text
    • http://tdvvietnam.vn/webroot/img/files/74232592200.pdfIn PDF document text
    • http://skazka76.ru/pic/userfile/83943421372.pdfIn PDF document text
    • https://mountainbrookbuilders.com/home/mountain/public_html/ckfinder/userfiles/files/86720329253.pdfIn PDF document text
    • https://giant-nano.com/app/webroot/userfiles/files/30833900772.pdfIn PDF document text
    • http://leeclinic.kr/userData/board/file/mijuvokulipemevojigaxelo.pdfIn PDF document text
    • http://www.siphonicflowmandiri.com/upload/files/tetoxirixixogimewufeleb.pdfIn PDF document text
    • http://sasnowosielski.com/ckfinder/userfiles/files/metuxajaduvatavu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=blocked+apps+on+androidPDF link annotation
    • https://easyown.ddproperty.com/datas/files/najinivofuvibufo.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_off0000d71f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD71F 17088 bytes
SHA-256: 9b3def285eb21c7ca992c1bcc843d8ca0cdea516558ca66514658943465b4209
font_01_sfnt_off00010350.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10350 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011b67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B67 10552 bytes
SHA-256: 63a53b948a67e9b8c98d715cac10104c27f187cac129f1aa97a242bd6b6c4732