Malicious PDF — malware analysis report

Static analysis result for SHA-256 e8c4e2a7f4ee77b2…

MALICIOUS

PDF

74.3 KB Created: 2021-09-19 09:49:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 579570b7f2d01f8777bc10bba97ba13c SHA-1: b45969ca4943accd7094d2806dcc6fccf338495c SHA-256: e8c4e2a7f4ee77b28a11a251c338cef5c0082f97f7e4d787ff60fb1ab04c8f22
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users. The presence of numerous external URLs, many of which appear to be part of a link farm, further indicates a phishing or malware distribution attempt. The primary technique observed is the use of JavaScript to potentially download and execute a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9885

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://synerhu.ru/uplcv?utm_term=nioh+2+sohaya+garb+smithing+text PDF link annotation
    • http://symbioticlifetech.org/attfile/fckimg/file///20210918183231_740299870.pdfIn PDF document text
    • http://tnmetalworks.com/images/files/gikaxonagolejidaweta.pdfIn PDF document text
    • https://ostrichpharmaceuticals.com/userfiles/file/sivadazatix.pdfIn PDF document text
    • http://raczcsalad.hu/files/gixapogawilipezikobuwa.pdfIn PDF document text
    • https://total-sport.pl/img/upload/files/dupifizimukavatu.pdfIn PDF document text
    • http://metabolitplus.ru/files/file/kuvifapidalagisuxiwus.pdfIn PDF document text
    • http://sp3siemianowice.pl/userFiles/files/mezukoza.pdfIn PDF document text
    • http://rentaruedas.com/files/others/151746598.pdfIn PDF document text
    • https://sealskinz.ru/files/file/64379591230.pdfIn PDF document text
    • https://athensviptour.com/wp-content/plugins/super-forms/uploads/php/files/f2786c60356a4a967f57764f08eb3b68/63943899009.pdfIn PDF document text
    • https://noticky.net/akce/fotky/file/29322013594.pdfIn PDF document text
    • http://chamdure.com/DATA/files/nezigerilatilotijalor.pdfIn PDF document text
    • http://quimis.org/js/ckfinder/userfiles/files/2309351409.pdfIn PDF document text
    • https://tuinvandecruys.be/file/798048505.pdfIn PDF document text
    • https://rsvforum.com/userfiles/file/44379392496.pdfIn PDF document text
    • http://partner-support.net/user_data/userfiles/files/78012940331.pdfIn PDF document text
    • http://emachn.com/data/attachment/file/69985036533.pdfIn PDF document text
    • http://atanasijornet.net/uploads/ckfinder/files/rimikewoda.pdfIn PDF document text
    • http://originalcheck.it/public/img_admin/file///38276336045.pdfIn PDF document text
    • http://photopuzzle.net/userData/board/file/ragilibuxe.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614539e004d74---penolatuzolofijenite.pdfIn PDF document text
    • http://jlm-kg.com/uploads/file/19954816463.pdfIn PDF document text
    • https://dichocungtoi.com/userfiles/file/datofapimojetigasola.pdfIn PDF document text
    • https://spa-salon.ru/ckfinder/userfiles/files/fidexinum.pdfIn PDF document text
    • https://bonvoyageindia.in/ckfinder/userfiles/files/967000668.pdfIn PDF document text
    • https://betsin.org/userfiles/files/pazakuxadixiwa.pdfIn PDF document text
    • https://aldwalia.com/userfiles/files/pajituxa.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_off0000bc51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC51 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d463.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD463 17064 bytes
SHA-256: 5d828d6a0c575467333398865dfe12a971c6985dc7118d27a5db9fec50b34046
font_02_sfnt_off00010079.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10079 10964 bytes
SHA-256: c47fcbb5f479fe6d0155230f20243a0cc16c8792d3f4fe31f053eb32f881f4f1