Malicious PDF — malware analysis report

Static analysis result for SHA-256 832c709b75748f83…

MALICIOUS

PDF

71.6 KB Created: 2021-09-17 09:26:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f971012453ece80f4aeadc22b7649fc4 SHA-1: 5db1b1bd55348eb173c9c69eaade5a3cb725572e SHA-256: 832c709b75748f83ec4d12c72d9edb56e9394806166460405217000bec1f55f7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to external sites, some of which are identified as link farms, suggesting a phishing or malware distribution scheme. The presence of PDF-specific heuristics like PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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://ketchas.ru/uplcv?utm_term=zmiana+g%C5%82osu+podczas+rozmowy+android PDF link annotation
    • http://sladkiy-ostrov.ru/userfiles/files/66642203846.pdfIn PDF document text
    • http://sbriz.ru/userfiles/file/woruwadelovurilubu.pdfIn PDF document text
    • http://fixafilm.se/userfiles/file/27488324164.pdfIn PDF document text
    • http://bm-shower.com/userfiles/files/jejejip.pdfIn PDF document text
    • https://viettrungson.com/media/Files/51043693273.pdfIn PDF document text
    • https://molecult.metallo-tests.ch/sites/web/upload/files/xeriwutiwur.pdfIn PDF document text
    • https://facades-et-traditions.com/actualites/file/34483967030.pdfIn PDF document text
    • http://www.lovebliss.tw/UserFiles/files/25733150183.pdfIn PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c1b3a170ca---45877255851.pdfIn PDF document text
    • https://adeptos.clevercloud.pt/images/items/files/48302308906.pdfIn PDF document text
    • http://cainghienbinhduong.com/uploads/userfiles/file/rezalanorurilik.pdfIn PDF document text
    • http://szjwwj.com/userfiles/file///kurulovakaxojagof.pdfIn PDF document text
    • http://folientastaturen.pl/_data/file/tuvusoraramugos.pdfIn PDF document text
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/buwovekofokogudikogofawot.pdfIn PDF document text
    • http://bidadapatidar.com/userfiles/file/sirejipikadibisekogepasa.pdfIn PDF document text
    • http://ibookingkr.com/FileData/ckfinder/files/20210903_498D6F0988585142.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16139d338e0fcf---lovikojovekuse.pdfIn PDF document text
    • http://studiofapas.it/userfiles/files/wenirukib.pdfIn PDF document text
    • http://www.halpellet.hu/userfiles/files/jusowojako.pdfIn PDF document text
    • http://atek-ent.com/upload/file/97144793475.pdfIn PDF document text
    • https://luatsubienhoa.com/upload/ck/files/memefoxugotomujuraw.pdfIn PDF document text
    • https://stephan-kratt.de/data/reiterhof/userfiles/file/1336139802.pdfIn PDF document text
    • http://spzpoz-zdunskawola.pl/upload/file/voravas.pdfIn PDF document text
    • http://seowonbattery.com/files/fckeditor/file/203934626861332591d6a50.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://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_off0000b928.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB928 16084 bytes
SHA-256: e0cff31664e992bc2b5d69a82edd567f11df5353348c360eb757d00a921eecf7
font_01_sfnt_off0000e122.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE122 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f939.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF939 10972 bytes
SHA-256: 1669ccdeeff415453bcdc2b6c6e28ca5e8a0e7f9de0c3c87492022ff46fc0e21