Malicious PDF — malware analysis report

Static analysis result for SHA-256 926e45c678792887…

MALICIOUS

PDF

77.3 KB Created: 2021-09-10 11:55:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 055780e180fee772fb94edafe65b1076 SHA-1: 175176d605af1cffb282b1fb013cbff0d1745d46 SHA-256: 926e45c67879288773ea8d170007d9f8fe609ca5bf0449e47f8b00e661fb89ce
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF structure, characterized by a large number of external links to potentially disposable domains, suggests it functions as a link farm. While no scripts were explicitly extracted, the PDF format itself can embed JavaScript, which is often used to redirect users or initiate downloads, aligning with the 'Spearphishing Attachment' technique.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://seibyou-koujien.com/files/files/43018287131.pdf In PDF document text
    • http://uralcomservis.ru/crn_fls/crn_files/razanerirovogude.pdfIn PDF document text
    • https://tierlistei.ch/downloads/32637061485.pdfIn PDF document text
    • http://viettelhaiphong.me/data/dulieu/files/15542649439.pdfIn PDF document text
    • http://georgekoldun.com/var/upload/file/mamifalobevulomexiwakot.pdfIn PDF document text
    • https://euronet.stonavka.cz/webpagebuilder/ckfinder/userfiles/files/mutevefugapakosiruzine.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/mutaso.pdfIn PDF document text
    • http://jmyhship.com/uploadfile/files/nebizozoravewujaraniweran.pdfIn PDF document text
    • http://abpjseah.news-read.com/upload/files/64233900042.pdfIn PDF document text
    • https://bangprice.com/bangprice.com/beta/cms_image/file/fovujifakunamotodo.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-9/20210909010242111697.pdfIn PDF document text
    • https://safrano.pl/userfiles/file/nebusozimarajudasukem.pdfIn PDF document text
    • https://kfk-dekoration.dk/images/uploadedimages/file/fasorelar.pdfIn PDF document text
    • http://amadesafar.ir/basefile/amadesafarir/files/kubokorosatufujozikevodek.pdfIn PDF document text
    • http://kooijobs.in/ckfinder/userfiles/files/rezuriludulasorava.pdfIn PDF document text
    • http://henanshuangxin.com/d/files/10724123685.pdfIn PDF document text
    • https://tranduongauto.com/app/webroot/files/images/pages/files/43964644479.pdfIn PDF document text
    • http://studiopiergentili.it/userfiles/files/41555397337.pdfIn PDF document text
    • https://toscanafantastica.com/userfiles/file/86224797446.pdfIn PDF document text
    • http://www.guus.edu.mn/ckfinder/userfiles/files/govegedenugovubegabugur.pdfIn PDF document text
    • http://educasters.co/ckfinder/userfiles/files/45379931334.pdfIn PDF document text
    • http://top1np.com/ckfinder/userfiles/files/pozivabate.pdfIn PDF document text
    • https://dodatkireklamowe.pl/web/uploads/files/35792266615.pdfIn PDF document text
    • http://nokianhakkablue.ru/ckfinder/userfiles/files/wevis.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=download+dragon+ball+z+live+wallpaper+for+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_off0000cb37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB37 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e34e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE34E 10760 bytes
SHA-256: d043bc6a86f1e1027908f4973bfe0de233834e0f8a1e69ad6516d459d277f9ea
font_02_sfnt_off0000fbc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBC7 16948 bytes
SHA-256: 54ebcbed8f32cdf2ee6b1403c334ab0049190fe1ff11729ac1a2b7b923f97c4c