Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb4a77ba39198fc8…

MALICIOUS

PDF

71.8 KB Created: 2021-09-11 08:46:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 979bf33dd41160254a7a85571b61807d SHA-1: ac8d1c0b34cee837eebd227e422c335471cefccd SHA-256: bb4a77ba39198fc8640ab1f79abdf0b31107b87f69cdb1f59428db7792d4da7d
134 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the redirection to external URLs, as evidenced by the numerous PDF_URI and EMBEDDED_URL heuristics, which are often used in phishing campaigns or to download further malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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
  • 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 https://sukienmiennam.com/userupload/files/duxoge.pdf In PDF document text
    • http://konberdbio.com/upload/files/87466941064.pdfIn PDF document text
    • http://sallytour.com/FileData/ckfinder/files/20210909_9A73D9E0F530FFD2.pdfIn PDF document text
    • https://mrpressconsulting.com/UserFiles/file/rufubibifepevip.pdfIn PDF document text
    • https://somogyplusz.hu/files/bazuxokel.pdfIn PDF document text
    • http://dryoucosmeceutical.com/userfiles/files/35955187566.pdfIn PDF document text
    • https://ipekyolumedya.com/resim_galeri/file/tejekifazetixin.pdfIn PDF document text
    • http://www.coverseg.com/uploads/ckfinder/files/rexolozidutexeza.pdfIn PDF document text
    • https://nutstudio.it/userfiles/file/56728033787.pdfIn PDF document text
    • http://ayhancevik.com/images_upload/files/14454678605.pdfIn PDF document text
    • http://datcat.vn/2018/file/4496713654.pdfIn PDF document text
    • https://cdmsig1.com/ckfinder/userfiles/files/wusaregejulujiza.pdfIn PDF document text
    • https://keyword-lda.pt/site/upload/file/76881206039.pdfIn PDF document text
    • https://egc.ecrom.work/syo/files/73022181709.pdfIn PDF document text
    • http://cheumst.com/upload/fckeditor/file/65082051694.pdfIn PDF document text
    • https://certifiedcollisionrepair.com/home/cert/public_html/ckfinder/userfiles/files/webova.pdfIn PDF document text
    • http://wasserentkalkung.at/ckfinder/userfiles/files/furorugofokowakeja.pdfIn PDF document text
    • http://designbyjoseph.com/uploads/File/57048840875.pdfIn PDF document text
    • https://saglamahsapkutu.com/img/editor/image/file/rukixenu.pdfIn PDF document text
    • http://skonasystems.com/userfiles/file/sidelabizinevabudiv.pdfIn PDF document text
    • http://erpos.sk/data/files/73006336236.pdfIn PDF document text
    • http://elateridae.com/images/FCKeditor/file/rusudepeb.pdfIn PDF document text
    • http://hospitalityroyal.com/upload_files/file/gozasijisinozuxigekozifa.pdfIn PDF document text
    • https://pu-sk.com/app/templates/js/ckfinder/userfiles/files/wefiledawerebogusatidatiw.pdfIn PDF document text
    • https://thieumaunao.vn/workspace/develop/uploads/ck_upload/files/gakemokipenorugi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=pubg+korean+version+download+in+androidPDF 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_off0000b6fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF13 10812 bytes
SHA-256: 96c3b2c937eb5c88dc06f158857075ad604b0eb18667da5ecedbdbde547731d4
font_02_sfnt_off0000e7f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7F2 16364 bytes
SHA-256: cf704a24b96dbb5ceced2b49de11fc8638beb3a7f8a659dc5e971cfac2530fcb