Malicious PDF — malware analysis report

Static analysis result for SHA-256 d639d19f9b45c8af…

MALICIOUS

PDF

81.6 KB Created: 2021-09-16 08:10:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d7167519d4e89c0ba3c53a08207bcb8b SHA-1: 2842a04993c85aeb5550aa3a6285f2edf448ed20 SHA-256: d639d19f9b45c8af3f3f49ca288c1e976c1e4c706cd0de05072e63f1d2e6cffc
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is designed to host a large number of links on disposable domains, likely for SEO manipulation or to distribute further malicious content. While no scripts were explicitly extracted, the presence of embedded URLs points towards a phishing or spam campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://nhatminhtrading.vn/app/webroot/uploads/files/79207739739.pdf In PDF document text
    • http://musicandyouapp.com/webupload/editorimg/files/6199551007.pdfIn PDF document text
    • https://luiginoiobbi.com/userfiles/file/13271287428.pdfIn PDF document text
    • http://belean.pl/userfiles/file/joxexobekezob.pdfIn PDF document text
    • https://deesudcoolingtower.com/userfiles/file/51807847408.pdfIn PDF document text
    • http://security-m.jp/tool/images/file/lafozogakutumibuxos.pdfIn PDF document text
    • http://fsgzb.com/upfolder/e/files/20210906105717.pdfIn PDF document text
    • http://www.corazondelsol.es/ckfinder/userfiles/files/lazimubigakov.pdfIn PDF document text
    • http://runbo.net/upfiles/files/16310334657210.pdfIn PDF document text
    • http://hutnia.pl/userfiles/file/43922071307.pdfIn PDF document text
    • http://alothongtin.com/upload/FCK/file/20218682213.pdfIn PDF document text
    • https://nichecnk.leaddeehub.com/userfiles/files/5667181181.pdfIn PDF document text
    • https://www.syria-report.com/sites/all/libraries/ckfinder/userfiles/files/wafapupoz.pdfIn PDF document text
    • http://diysmart.net/userfiles/file/nixijupi.pdfIn PDF document text
    • http://golfproradost.cz/webpagebuilder/ckfinder/userfiles/files/90950915140.pdfIn PDF document text
    • http://beiks.info/public/file/27186885034.pdfIn PDF document text
    • https://remoteyourstaff.com/calisma2/files/uploads/nunugebinaxazavuza.pdfIn PDF document text
    • http://huijingweb.com/upload_fck/file/2021-9-4/20210904175253969586.pdfIn PDF document text
    • https://fotobolfestmeny.hu/mvc/userfiles/file/4360508435.pdfIn PDF document text
    • https://best-label.com/upload/files/rivekewumawidota.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613cccc82fa8d---ratorumunuvizolatesejo.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/b4586614e5c2a7db872a0e21e9435e05/topiduvozo.pdfIn PDF document text
    • https://searchlink.org/userfiles/file/12089828967.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=badman+client+minecraft+bedrockPDF 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_off0000d392.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD392 10752 bytes
SHA-256: c8fa2ee61e01747abc3c136180ff4a37de058a76628d9a3f2f6dcb9365ce4b32
font_01_sfnt_off0000ec3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC3F 19772 bytes
SHA-256: 8fd7da9dd0fcf41c9678d7f74a967cf2ac2056c5badf176e14f5a711b9536ae1
font_02_sfnt_off0001205e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1205E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1