Malicious PDF — malware analysis report

Static analysis result for SHA-256 50ec51f129a70103…

MALICIOUS

PDF

82.8 KB Created: 2021-09-17 18:51:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 3850be2ee110c6d9b2238e23ecaae3c3 SHA-1: 614a8d34e90e9ab124f8e08c5804561bec519a5c SHA-256: 50ec51f129a70103e129580b0d9b6824e13e0beaa6e15abafa178dfda24a52e7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URLs, many of which are part of a link farm hosted on disposable domains, suggesting an attempt to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics indicate a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://crysiq.ru/uplcv?utm_term=toefl+book+pdf+audio+download PDF link annotation
    • https://ladymamashop.com/uploads/files/202109120402013655.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/16137c5c1b0424---gamawuwogonidi.pdfIn PDF document text
    • http://frutapac.com/ckfinder/userfiles/files/tujogejemizazizegibolunig.pdfIn PDF document text
    • http://aorganboys.handyfriendship.com/upload/files/nuwejo.pdfIn PDF document text
    • http://softtox.pl/new/userfiles/file/vamuxisizifulotegap.pdfIn PDF document text
    • http://halaljones.com/uploads/files/malajozesifitifer.pdfIn PDF document text
    • https://speculatio.in/userfiles/file/72537752579.pdfIn PDF document text
    • http://condosworld.com/abisol1/userfiles/files/povaxaseganuwunuzu.pdfIn PDF document text
    • http://srmtteaparty.com/uploads/files/202109090703335397.pdfIn PDF document text
    • https://culturasiapamplona.com/guiarte_userfiles/files/samasak.pdfIn PDF document text
    • https://jcmimoveis.com/userfiles/file/64200193427.pdfIn PDF document text
    • http://fitviewer.info/files/file/baveluf.pdfIn PDF document text
    • http://the-bom.kr/upfile/files/27726548674.pdfIn PDF document text
    • http://richardchong.com/userfiles/files/teludekegekomepenolosep.pdfIn PDF document text
    • https://amgaa.org/temp/files/suvowusuxozokezazobaxijuf.pdfIn PDF document text
    • https://copacndg.com/images/uploads/files/zirixuzu.pdfIn PDF document text
    • https://giaynangchieucao.com/userfiles/file/kibowilopagikulida.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613c8f8993198---kosiziwa.pdfIn PDF document text
    • http://aedjtjdshbf.pretty-match.com/upload/files/sejiju.pdfIn PDF document text
    • https://xn--pssa17sw71b.tw/upimages/files/xunajetu.pdfIn PDF document text
    • http://samocvet.org/foto/ck/files/delanepelofitigumew.pdfIn PDF document text
    • https://opsclown.it/ckfinder/userfiles/files/15107657303.pdfIn PDF document text
    • http://iscelenie.info/files/file/figagarapad.pdfIn PDF document text
    • http://coverybox.box8websites.com/ckfinder/userfiles/files/79583459769.pdfIn PDF document text
    • http://domgr11.ru/uploads/files/32297362237.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_off0000df15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF15 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f72c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF72C 10508 bytes
SHA-256: f47f3cad91241d9f568157ee3216ee9bac18f9ff991a4c331964706092305466
font_02_sfnt_off00010ef6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EF6 18020 bytes
SHA-256: 8db04a24e022450badc27e98a447329a21a8e5c84d05912c3d73565b4a85c56c