Malicious PDF — malware analysis report

Static analysis result for SHA-256 df8b2eff21412edc…

MALICIOUS

PDF

73.6 KB Created: 2021-09-26 10:55:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9b9b0caca7651ab7c580ba6b96233de3 SHA-1: 11ab1b0d4af39840f381e3e47c9664c3467498a3 SHA-256: df8b2eff21412edc8dd6b645c8050026b353035f6819a5a9438141a881d357a7
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, 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 for phishing or distributing further malware. The presence of embedded URLs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic confirm the document's purpose is to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://crewmak.ru/uplcv?utm_term=gta+real+life PDF link annotation
    • http://csaladiegyteruautok.hu/userfiles/files/jumabakegufezi.pdfIn PDF document text
    • https://rallstarawards.us/nbloom/fckuploads/file/85744380250.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d2baf93bf9---rikurepepidanulatubus.pdfIn PDF document text
    • http://locum-system.pl/userfiles/file/77768014590.pdfIn PDF document text
    • http://shethof.ch/cgi-bin/dynamisch/file/getuwif.pdfIn PDF document text
    • https://doanhnghiepvietnam.org/img_duhoc/files/70482188038.pdfIn PDF document text
    • http://hengtongrongshang.com/jingkelun/userfiles/files/20210925172251.pdfIn PDF document text
    • http://back2wood.de/userfiles/file/pidukalisagubarulul.pdfIn PDF document text
    • http://koryosushi.com/uploads/files/jusanexonejoso.pdfIn PDF document text
    • https://architektor.ru/uploads/file/folod.pdfIn PDF document text
    • https://interstudy.net/userfiles/file/kanizavetenitawone.pdfIn PDF document text
    • http://logtech.cz/foto/Image/file/65867635186.pdfIn PDF document text
    • http://itagqatar.com/itag/file/files/35644491071.pdfIn PDF document text
    • http://studioarchperissinotto.eu/userfiles/files/79767578441.pdfIn PDF document text
    • http://evo-models.com/uploads/userfiles/files/suwigazuzosabokujutu.pdfIn PDF document text
    • http://asacnfservices.com/ckfinder/userfiles/files/metutubuzugodivaluvuvuse.pdfIn PDF document text
    • http://ad.ditroinfotech.com/laportal/ckeditor-ckfinder-integration/uploads/files/tisisalakumixomorekonero.pdfIn PDF document text
    • http://luluscafeonline.com/uploads/files/renuxa.pdfIn PDF document text
    • http://marine-inox.com/i/File/1274915026.pdfIn PDF document text
    • http://normel.org/files/upload/file/vuworemibidixatabup.pdfIn PDF document text
    • http://ambulatorioveterinariobubiniregini.eu/userfiles/files/80620301159.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/6a38c1709e6f501acd9d3447b7f2ecfe/93833587043.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_off0000bc9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC9B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d4ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4AD 17924 bytes
SHA-256: 07ba8c37874e7bad792beef0b57672d9edac07d77caca9f61f4cd7320d289561
font_02_sfnt_off0001033c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1033C 9856 bytes
SHA-256: e11ec2eea9cdec8cffe5b90d5ea59c28cea123f0fe5398287cf6fdcc0663b626