Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b99a31df00d46c3…

MALICIOUS

PDF

70.7 KB Created: 2021-10-08 00:56:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: a3709b43b8b9b0b6aba0457fd8ea84fa SHA-1: 35ba19477ddbb80b0c2d3b08e9b5ade39dc3bf44 SHA-256: 7b99a31df00d46c3a52c89c4a34987fdf0d336aa46cb1b22131003167ba67fed
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. The file contains a large number of embedded URLs, many pointing to disposable hosting, suggesting a link farm or phishing lure. The ML classifier also strongly indicated maliciousness. No scripts were extracted, but the sheer volume of external links points towards an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

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 https://cructi.ru/uplcv?utm_term=how+to+paint+over+gloss+skirting PDF link annotation
    • http://vvk-wiedermann.at/userfiles/file/4215176154.pdfIn PDF document text
    • http://hamishehbaharcarpet.com/My_Project/Hamishe_bahar/ahar_img/files/74949629187.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1614d06d86d188---65893010740.pdfIn PDF document text
    • https://whitesal.com/data/images/file/7715_20210907194336.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/70edb5771369f95d5a392db9d8f4de29/rexaridoref.pdfIn PDF document text
    • https://zippy-inc.com/app/webroot/userfiles/files/77679553087.pdfIn PDF document text
    • https://minhvuongthuphap.com/upload/ck/files/20627866814.pdfIn PDF document text
    • https://riolospettacoli.it/filesUploads/file/9671707249.pdfIn PDF document text
    • http://innovarhomes.com/cms_images/file/92849793678.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613e35c7336a6---82581258199.pdfIn PDF document text
    • https://derfo.info/resimler/files/todalenekux.pdfIn PDF document text
    • http://dtyxbpzx.com/filespath/files/20210919114730.pdfIn PDF document text
    • https://tainandentist.com/uploads/files/202109091107042233.pdfIn PDF document text
    • http://asja-doll.ru/userfiles/file/47083766404.pdfIn PDF document text
    • http://vladjurnalist.ru/archive/file/35404668193.pdfIn PDF document text
    • http://www.enredmail.com/templates/files/idCliente_/file/26323527740.pdfIn PDF document text
    • http://mvpbuilding.com/userfiles/file/37218898887.pdfIn PDF document text
    • http://makesomenoise.hu/upload/file/52561760145.pdfIn PDF document text
    • http://dworbieland.pl/userfiles/file/rujujom.pdfIn PDF document text
    • http://dreamwith.gni.kr/ckupload/files/85886848040.pdfIn PDF document text
    • http://eichler-kammerer.de/79061629823.pdfIn PDF document text
    • https://xn--nmqu14inmf.com/upload/files/rujakotatiwojixilofub.pdfIn PDF document text
    • https://calprin.com/ckfinder/userfiles/files/8937158237.pdfIn PDF document text
    • https://unitjaya.com/contents/files/21321590429.pdfIn PDF document text
    • https://pmfegypt.com/userfiles/files/dimer.pdfIn PDF document text
    • https://cremyco.com/app/webroot/docs/file/95613431666.pdfIn PDF document text
    • https://longhungphat.org/Images_upload/files/25418866709.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_off0000b6c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6C5 10660 bytes
SHA-256: a208aef95cbe7e3364117476046e293c55d67a1c9a06904281a1a0eb4febc762
font_01_sfnt_off0000cf5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF5F 14804 bytes
SHA-256: d5a8268df48c47fbf1301a739c5d95fc2b491c500a0444efd75f945393cc4190
font_02_sfnt_off0000f46c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF46C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1