Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1137bed42e11fdd…

MALICIOUS

PDF

79.3 KB Created: 2021-09-20 03:29:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: d55b4dba60b10ebbaec5153b3e04aa28 SHA-1: 9670459d32661ad8847e5202428d748b14b444ec SHA-256: c1137bed42e11fddf603e4bbd92ca49f4d16a0fae29a20703066f4dc90c6d271
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ML and ClamAV as malicious, with heuristics indicating it functions as a link farm. It contains numerous embedded URLs pointing to other PDF files hosted on various domains, many of which appear to be disposable or low-reputation. This suggests a phishing or malware distribution scheme where the initial PDF serves as a lure to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://katour.ru/admin/ckfinder/userfiles/files/bivegozonuz.pdf In PDF document text
    • http://diysmart.net/userfiles/file/zifase.pdfIn PDF document text
    • http://romanasulcikova.cz/userfiles/wedagevepazex.pdfIn PDF document text
    • https://avukatwebsitesi.kocgrafik.net/upload/files/musoviseneseba.pdfIn PDF document text
    • http://jfhcoaching.com/userfiles/files/gobovi.pdfIn PDF document text
    • https://dtd.com.pk/ckfinder/userfiles/files/resov.pdfIn PDF document text
    • http://nomorecpapmachine.com/userfiles/files/82529227279.pdfIn PDF document text
    • https://duongthuy.net/userfiles/file/sujefesijupawanefiru.pdfIn PDF document text
    • http://sksound.com/userfiles/file/fadodowigidojajowimupid.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137744ab7f1f---rotoloxoripanepuvolu.pdfIn PDF document text
    • http://sz-nuoyi.com/Upload/file/2021090615571628802.pdfIn PDF document text
    • http://paykaaluminiya.ru/ckfinder/userfiles/files/wimusunakenezofinal.pdfIn PDF document text
    • http://archi-m.ru/userfiles/file/sulajitanopoberukuriv.pdfIn PDF document text
    • https://cpsguffanti.it/uploads/file/57518758140.pdfIn PDF document text
    • http://xn--h1agcmh.com/ckfinder/userfiles/files/duzubunulotatuzumino.pdfIn PDF document text
    • http://location-appartement-venise.com/italie_documents/files/sutepalapezokoxulawe.pdfIn PDF document text
    • https://delaneyllc.com/ckfinder/userfiles/files/lotodisawinimixomog.pdfIn PDF document text
    • http://intertribo.sk/files/53718777172.pdfIn PDF document text
    • http://kleinschaden-expert.com/userfiles/file/bavanufegus.pdfIn PDF document text
    • https://shiprapublication.com/uniformkontakt/userfiles/image/files/80870093690.pdfIn PDF document text
    • http://kommunikator.nu/demo/userfiles/file///3610357988.pdfIn PDF document text
    • https://kawanmto.net/contents/files/83896687172.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613e534f770e7---19601411995.pdfIn PDF document text
    • https://artistaone.co/userfiles/files/60869035886.pdfIn PDF document text
    • http://mtcongnghiepxanh.com/upload/fckimagesfile/fenusiwezo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=screen+record+android+studioPDF 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_off0000d0a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e8b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8B8 17908 bytes
SHA-256: 9dccda8dd7a900d32318aea5bd06aa8242be589bff79ac09204af6897c93f67c
font_02_sfnt_off000117b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117B9 10492 bytes
SHA-256: 4264d4b8ac112af8df230852ff71b16de4cbf293d6e7d9428f58aa254852f1cd