Malicious PDF — malware analysis report

Static analysis result for SHA-256 31483a840b7d063e…

MALICIOUS

PDF

82.9 KB Created: 2021-09-22 13:05:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 5006f455b3bd7a7d15cc02d999074bc8 SHA-1: dfc55de12721662484baa910fd283a7d0b7ce359 SHA-256: 31483a840b7d063e4a79360fae3e577d6d0fa851d0aba34538e34bb2c301ff5e
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many hosted on disposable domains, suggesting a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/8eckf5m1b0ls0p37a1q1msemp6/matedug.pdf In PDF document text
    • http://lmnn.ru/userfiles/file/xeteleta.pdfIn PDF document text
    • https://pelicanfinancialnetwork.net/ckfinder/userfiles/files/44115710393.pdfIn PDF document text
    • https://dangeloremodeling.com/nbloom/fckuploads/file/45276265302.pdfIn PDF document text
    • http://dinskayarealty.ru/media/file/3426492802.pdfIn PDF document text
    • http://yonseri.org/userfiles/files/23608096114.pdfIn PDF document text
    • http://mbfeed.vn/upload/files/pumisetebixorani.pdfIn PDF document text
    • http://bielwod.com/userfiles/file/lofolalu.pdfIn PDF document text
    • https://ambulatorioveterinariosismondi.eu/file/xijebojugidagoned.pdfIn PDF document text
    • https://smartbrand.ro/mm/file/bebasejale.pdfIn PDF document text
    • http://jikaramen.com/uploads/files/54336854958.pdfIn PDF document text
    • http://kovofilm.cz/userfiles/file/49951425705.pdfIn PDF document text
    • http://vector-food.pl/userfiles/file/50138424790.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612fe33969505---37319748448.pdfIn PDF document text
    • http://oletrans.sk/editor_uploads/files/73740919118.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/javidarakosuriraroxi.pdfIn PDF document text
    • http://bratislava.topenglish.sk/app/webroot/gallery/files/55864701578.pdfIn PDF document text
    • http://shepardinteriordesign.com/rw/upload/file/xefokepadom.pdfIn PDF document text
    • http://biznesfishki.ru/files/userfiles/files/relasotiw.pdfIn PDF document text
    • https://mosaicopeoplecorporation.com/ckfinder/userfiles/files/44515392987.pdfIn PDF document text
    • https://dbjadow.pl/attachments/file/filedusenifipenepax.pdfIn PDF document text
    • http://ylgems.com/file_media/file_image/file/gudizolosakulamiruja.pdfIn PDF document text
    • https://letajicikoberce.cz/userfiles/file/19225719351.pdfIn PDF document text
    • https://www.auto-ecole-acm.com/ckfinder/userfiles/files/zubodimi.pdfIn PDF document text
    • http://abwingscolley.com/uploads/files/83715432030.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=app+to+watch+series+freePDF 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_off0000e183.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE183 10492 bytes
SHA-256: b4fc389c23f9df4531854f899cf7b456f763f208df4905fe16e0ac1f0494b9e1
font_01_sfnt_off0000f9a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9A4 17096 bytes
SHA-256: 63272e84933c575f739bfbfb88734e4189edb93502c26a42813dcf1fc1fe8f2e
font_02_sfnt_off00012591.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12591 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1