Malicious PDF — malware analysis report

Static analysis result for SHA-256 7d33cecb88304d51…

MALICIOUS

PDF

82.6 KB Created: 2021-10-01 09:43:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 57e2bdf4fc347c98ac36b05d492772ea SHA-1: 8741fb7aa957a411b15a704b9a41400ef4ef5b5c SHA-256: 7d33cecb88304d512b1616788361c8e097b584bc7b70dfb83bc7deb56df4a0bf
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high number of external URIs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The embedded JavaScript could be used to further obfuscate the malicious activity or redirect the user.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9938

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://irlanc.ru/uplcv?utm_term=kho+game+hay+cho+android PDF link annotation
    • http://weighlessthisyear.com/ckfinder/userfiles/files/jivipaf.pdfIn PDF document text
    • http://roland-toys.eu/userfiles/file/69106170319.pdfIn PDF document text
    • http://noithatmfc.com/media/ftp/file/xedixaserefasuz.pdfIn PDF document text
    • http://www.americaninvest.net/upls/files/15038875114.pdfIn PDF document text
    • http://dges.in/userfiles/file/14733996281.pdfIn PDF document text
    • https://yumasri.com/assets/ckfinder/userfiles/files/vonakikud.pdfIn PDF document text
    • https://preciseenergygroup.com/media/90529259977.pdfIn PDF document text
    • http://letsfinal.com/userfiles/file/noruxafiwo.pdfIn PDF document text
    • http://ipsaix.com/ckeditor/ckfinder/userfiles/files/noxogizatekelakemekufora.pdfIn PDF document text
    • http://financesnadno.cz/upload/file/kudemifubazofugixo.pdfIn PDF document text
    • http://portofmiamitunnel.com/system/js/back/ckfinder/userfiles/files/neruvubotiz.pdfIn PDF document text
    • http://www.binghan.my/userfiles/file/82598141221.pdfIn PDF document text
    • https://foursservices.com/nbloom/fckuploads/file/66679160795.pdfIn PDF document text
    • http://dansungsala.com/uploads/files/visebagokevomu.pdfIn PDF document text
    • http://veoguidecostarica.com/ci/userfiles/files/filepakivugekal.pdfIn PDF document text
    • http://decaiyun.com/upload/file/2109170455092972196es5l8ozchg3.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16131d426f3f91---66631304566.pdfIn PDF document text
    • http://herium.net/FileData/ckfinder/files/20210906_A8E1BB56DC7568B8.pdfIn PDF document text
    • https://podimercrm.com/img/files/kitunexidavifisolozuxareg.pdfIn PDF document text
    • http://watch62.ru/files/files/29586379112.pdfIn PDF document text
    • https://ltes2.tw-goods.com/UserFiles/files/serobogipavesavusetago.pdfIn PDF document text
    • http://website-design-company.in/dev3/damodar/ckfinder/core/connector/php/userfiles/files/49290804038.pdfIn PDF document text
    • https://vresponse.net/userfiles/file/gesinevupelik.pdfIn PDF document text
    • https://click2repair.chocoza.com/userfiles/file/mufemorelegogudezuve.pdfIn PDF document text
    • http://crmloccitanecr.com/campannas/file/43130567991.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000be8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE8C 20932 bytes
SHA-256: a15990d72c943dbe6af0540964646ab22257d9c62579c430678c1cfa6dc91b97
font_01_sfnt_off0000f4f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010d05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D05 16188 bytes
SHA-256: 800554d3d6320da9c8ab21a3ad3d270f40e7a92360d7538c059d647d952d1d34
font_03_sfnt_off000122bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122BC 10608 bytes
SHA-256: 409abf64a0f1db5b748479948db72bc2b5a5d857db3490be5d3bd7566e3026a0