Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad95b838a6f952fc…

MALICIOUS

PDF

87.1 KB Created: 2021-09-16 17:32:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 24309839654d8a240cde0ad63365900e SHA-1: c541c6756298ddb249fe1b8a89bcc9e1713eea36 SHA-256: ad95b838a6f952fca45d518fdd234937d35e40568caa0dcd73055f10ce79df12
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, with a high-confidence heuristic identifying it as a link farm on disposable hosting. One link points to an algorithmically-generated URL, and ClamAV detection confirms it as a phishing trojan. While no scripts were directly extracted, the PDF structure and link farm behavior strongly suggest an attempt to redirect users to malicious sites for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://tbsva.org/Upload/files/20210903225352.pdf In PDF document text
    • http://archiw.gbpopatowiec.pl/img/upload/files/98775313545.pdfIn PDF document text
    • http://sm.ac.th/ckfinder/userfiles/files/favigerijizuzefive.pdfIn PDF document text
    • http://popmetre.com/news/files/26824425713.pdfIn PDF document text
    • http://ambulatorioveterinariopisillibertozzi.eu/userfiles/files/65586375014.pdfIn PDF document text
    • https://apz-arte.com/ckfinder/userfiles/files/242613533.pdfIn PDF document text
    • http://kemenyseprosiklos.hu/upload/file/dotigimokawiwodetagap.pdfIn PDF document text
    • http://miraesusan.com/ckupload/files/92574338530.pdfIn PDF document text
    • http://gdfsztal.com/uploadfile/files/2161938652.pdfIn PDF document text
    • http://waetsukai.jp/system/ckfinder/userfiles/files/43992483645.pdfIn PDF document text
    • http://homeloanz.net/images/e/file/89441480902.pdfIn PDF document text
    • https://alshaabcoop.com/userfiles/file/67713298866.pdfIn PDF document text
    • http://twilaw.com/files/files/57670425753.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/f3dd19d549cd5985e4303e9cce4fe14f/sirajawivabagu.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/161398358a50ae---jukadajesudaxarawonaputo.pdfIn PDF document text
    • https://senesi-sklad.cz/userfiles/file/sufowawuliba.pdfIn PDF document text
    • http://www.brickchamber.com/ckfinder/userfiles/files/41060879060.pdfIn PDF document text
    • https://nexapos.com/upload/files/50563985025.pdfIn PDF document text
    • http://vakoplus.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/37799641166.pdfIn PDF document text
    • https://vendax.ro/files/file/41000049096.pdfIn PDF document text
    • http://www.medic-pneumolog.ro/fisiere/file/54785032440.pdfIn PDF document text
    • http://perlawarmii.pl/userfiles/file/dozabofusulomexapigixumub.pdfIn PDF document text
    • http://www.prieteniitehnicii.ro/documente/file/jokoli.pdfIn PDF document text
    • https://phunhai.net/upload/files/tazuze.pdfIn PDF document text
    • http://meditopthailand.com/file/sepubumibubemomijede.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=escape+games+for+androidPDF 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_off0000f0e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010900.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10900 10804 bytes
SHA-256: 76b502be3164efcdbcd0d04928e3850870826b434076e29abd969165935e76ed
font_02_sfnt_off000121a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121A1 17608 bytes
SHA-256: 830fa7f9339e6b219cc21b41491757b47273e914d7bfefadc7c34da517000820