Malicious PDF — malware analysis report

Static analysis result for SHA-256 5984a680b932ba8a…

MALICIOUS

PDF

75.9 KB Created: 2021-10-11 11:43:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: caadce63383bf5e30b4d26b1cc2450bd SHA-1: 375365757e8efafe519be032a5354228b6432b01 SHA-256: 5984a680b932ba8a59faf8471d0003793257135430025d1d85b49ccec467a294
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, with several heuristics flagging it as a link farm on disposable hosting and pointing to algorithmically-generated URLs. ClamAV detection and ML classification confirm its malicious nature. The primary attack pattern involves directing users to download further malicious PDF files from these external domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://nezrenpin.com/calisma2/files/uploads/rogemuxikaputagejipuweno.pdf In PDF document text
    • http://motolargo.pl/userfiles/file/didiveladavofinabezupo.pdfIn PDF document text
    • https://pikhospital.com/ck_uploads/uploads/files/28004609027.pdfIn PDF document text
    • https://brtim.com/uploads/wysiwyg/files/63953201505.pdfIn PDF document text
    • https://ceccarmehedinti.ro/userfiles/file/galebojavixejavag.pdfIn PDF document text
    • http://altinay-law.com/images/file/47367638441.pdfIn PDF document text
    • http://wwpokebar.com/uploads/files/73197372754.pdfIn PDF document text
    • http://mlight.cz/archiv/file/32162427964.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/1615a7ac451e3a---17218872808.pdfIn PDF document text
    • http://twapp.freshkon.com/upload/files/65818018345.pdfIn PDF document text
    • https://mimpishio.com/contents/files/basuluva.pdfIn PDF document text
    • http://bagodilovaspark.hu/userfiles/file/91212779575.pdfIn PDF document text
    • https://workinhotel.com/upload/fckfile/dazosem.pdfIn PDF document text
    • http://bbdecontra.com/userfiles/files/68658914948.pdfIn PDF document text
    • http://ambulatorioveterinarioilghirlandaio.it/userfiles/files/90715668951.pdfIn PDF document text
    • http://phongthuydotho.vn/upload/files/95655104779.pdfIn PDF document text
    • http://southerncross-ex.com/images/blog/file/36290027686.pdfIn PDF document text
    • http://tfh-filter.hu/_user/file/81775852333.pdfIn PDF document text
    • https://wroclaw-effatha.pl/grafiki/file/rafekema.pdfIn PDF document text
    • http://congress.bpv.su/content/files/files/49783365498.pdfIn PDF document text
    • http://roberthalasz.eu/uploads/file/numukemibolawixovu.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/44199577119.pdfIn PDF document text
    • http://profiklub.sanswiss.cz/files/file/xivenuxobobijumebimo.pdfIn PDF document text
    • http://debeight.net/UserFiles/File/91346958524.pdfIn PDF document text
    • http://mskgroup-spb.ru/upload/file/gobuzusabuso.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/HKUGBsJGI0E/uplcv?utm_term=construction+equipment+management+for+engineers+estimators+and+owners+pdfPDF 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_off0000c2fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2FB 11280 bytes
SHA-256: d0b368016e29170080ac643a7a39885a447dfbd207dccff7aa7d66c93c07814e
font_01_sfnt_off0000dd11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD11 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f523.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF523 17300 bytes
SHA-256: c3bdb449478506e032ed5242a2af78461433e8a5e4b186ab3009d677b0b96b3a