Malicious PDF — malware analysis report

Static analysis result for SHA-256 637de1fe36910ba8…

MALICIOUS

PDF

84.7 KB Created: 2021-09-18 12:07:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: c0a6cac4eeeb1b634d178afda01ca54f SHA-1: 2479b6cca06a36b8b60b079195fd6cb936a6f7d7 SHA-256: 637de1fe36910ba8e59865a593100927a58a744db92a3593bacaf24035fd37c0
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URLs, strongly indicating a malicious intent to either phish users or distribute further malware. The ClamAV detection and ML classifier output further support its malicious nature. The presence of embedded JavaScript suggests it is used to execute malicious code, likely to download and run a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://crewmak.ru/uplcv?utm_term=best+3d+game+engine+for+android PDF link annotation
    • http://profitoolinfo.ru/ckfinder/userfiles/files/zujetuvaboruwogopo.pdfIn PDF document text
    • http://planetamama.ru/files/file/wabot.pdfIn PDF document text
    • https://dammesliepas.lv/ckfinder/userfiles/files/xakerejuxotojotidoramub.pdfIn PDF document text
    • http://www.gulbaharsigorta.com/contentData/file/90213051829.pdfIn PDF document text
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/6e83725bddf3e3dcfe9d9dc4a2fe66e7/fegivevidakifelinofam.pdfIn PDF document text
    • http://tl-maskinfabrik.dk/userfiles/file/21863004615.pdfIn PDF document text
    • http://resheto.ru/users_images/fck/file/dakatiwajim.pdfIn PDF document text
    • https://cochleartudaskozpont.hu/files/gofatepakubuxojibizo.pdfIn PDF document text
    • http://chupanhnoithat.vn/upload/files/73280272864.pdfIn PDF document text
    • http://szjwwj.com/userfiles/file///jorosiravasisupeneku.pdfIn PDF document text
    • http://xn--9w3b270a7kf.kr/ckfinder/userfiles/files/miwivufotiru.pdfIn PDF document text
    • http://cuborh.com/natelinhanew/js/ckfinder/userfiles/files/76457251711.pdfIn PDF document text
    • https://ichapps.peaceofworld.com/ichapps/ckeditor-ckfinder-integration/uploads/files/70364015449.pdfIn PDF document text
    • http://hpcad.pl/Upload/file/sagabe.pdfIn PDF document text
    • https://kamhosting.nl/ckfinder/userfiles/files/tipepokakun.pdfIn PDF document text
    • https://ethnicminorities.heephong.org/ethnicminorities/cmsadmin/ckfinder/files/11223438382.pdfIn PDF document text
    • http://litroshaber.net/resimler/files/netabov.pdfIn PDF document text
    • http://synhbio.com/upload/files/75660711322.pdfIn PDF document text
    • https://gyn-koe70.de/obrazky/file/87406341447.pdfIn PDF document text
    • http://residencelesaline.it/userfiles/files/63778673307.pdfIn PDF document text
    • https://talenthunt.biz/userfiles/file/jetelijusufutometodege.pdfIn PDF document text
    • http://araonline.hu/uploads/file/tulewesunajedul.pdfIn PDF document text
    • https://www.nhabe.com.vn/ckfinder/userfiles/files/vawiroparitifodewexe.pdfIn PDF document text
    • https://fiscalonline.eu/app/webroot/files/userfiles/files/1079246709.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e2eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2EB 18480 bytes
SHA-256: b68e9f295cd667735b0c4c454fbf774f4c47cb2d11f3f70aeab179a3fd970ccf
font_01_sfnt_off000113b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012bcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BCB 10876 bytes
SHA-256: 99c1b912258fe22ce7ad7b1768f68c141e01d974845ff7968c9adf6e6cd5a6d4