Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd7fa8766021fd08…

MALICIOUS

PDF

92.0 KB Created: 2021-09-21 21:54:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5adf2d4d0a213303bfa87f7d2ef5ab42 SHA-1: 4c894624f37769fb4c2617050a48174850441d75 SHA-256: bd7fa8766021fd08f251cbc0e1c3e88c3bb6ba9d278dd48e0f7579c9336d6b67
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to numerous external PDF files hosted on disposable domains. The primary attack pattern involves luring users to these external links, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://yh-nutri.com/filespath/files/20210904193101.pdf In PDF document text
    • http://huh.hu/UserFiles/File/zabezepasinag.pdfIn PDF document text
    • http://barudan.hk/UploadFile/file/20210917024714823.pdfIn PDF document text
    • http://nfc-lampang.com/user_img/files/71582355901.pdfIn PDF document text
    • http://citescolairedeledit.com/include/file/70490550709.pdfIn PDF document text
    • http://chaodontuonglai.vn/uploads/ck_upload/files/xarajug.pdfIn PDF document text
    • http://bimbrlata.cz/UserFiles/File/21053546110.pdfIn PDF document text
    • https://dalba.net/other_files/File/sibezoxo.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/dd1c09bd57271b56d7668dbcd5e56284/21529477855.pdfIn PDF document text
    • http://pilanatofishing.com/home/sandbox/domains/shelter.sandbox.tritek.hk/public_html/ckfinder/userfiles/files/xufebes.pdfIn PDF document text
    • http://laros.cz/UserFiles/file/38164025637.pdfIn PDF document text
    • http://kaithompson.com/userfiles/file/30376046138.pdfIn PDF document text
    • http://nissanotogovap.com/uploads/images/files/nejerexasiguri.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1614443ea06685---42750586694.pdfIn PDF document text
    • http://radecznica.pl/userfiles/file/80199801888.pdfIn PDF document text
    • https://gagiongvitgiong.com/ckfinder/userfiles/files/83500222749.pdfIn PDF document text
    • https://regionalhealthprogramsww.com/images/file/72573996702.pdfIn PDF document text
    • http://aylincinarli.com/fckfiles/file/70467872900.pdfIn PDF document text
    • http://willettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/21861900276.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16147355c6a395---bikutot.pdfIn PDF document text
    • https://produktybhp.pl/pliki_user/File/gavibulajodidup.pdfIn PDF document text
    • https://dusunceokulu.net/resimler/files/38342497930.pdfIn PDF document text
    • http://suncitygroup.ir/basefile/suncitygroupir/files/27180728397.pdfIn PDF document text
    • http://architettosbaffo.com/userfiles/files/48269970132.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=pogo+spoofing+appPDF 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_off000103b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B2 10156 bytes
SHA-256: 1c02bb93342e3de02746eb2f6e11e45154a14d7898f9a19799bc9e4a9992bce5
font_01_sfnt_off00011a86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A86 18344 bytes
SHA-256: 8dfa4ea538f0552f7f3cc0e40562bfd91c63cccf74525807b21ca04691625a32
font_02_sfnt_off00014a6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A6A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1