Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f9ff733d2360734…

MALICIOUS

PDF

77.3 KB Created: 2021-09-22 20:47:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: dac22666ece555815c99d31735078673 SHA-1: c318dcbedacd37fba913d1d7303067b708ba9557 SHA-256: 3f9ff733d23607348e1d609ba5c60819d0284feee8f3bb4d3ad42eb7b2f5a9b6
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file that contains a link farm pointing to other PDFs hosted on compromised websites, a common tactic for phishing and malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of embedded URLs and the nature of the heuristics suggest the document is designed to trick users into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://veoguidecostarica.com/ci/userfiles/files/novaxanajukovijaw.pdf In PDF document text
    • https://stthomasorthodoxchurchsouthpampady.com/userfiles/file/mutafodu.pdfIn PDF document text
    • http://antoniolescio.net/userfiles/files/pujebalote.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/7dtnqkjrq5ndtikt4caajt0at7/61419031794.pdfIn PDF document text
    • https://asken.as/bilder/file/70531674434.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/b3176b9cb1059996e61f97e35283a322/ladukuma.pdfIn PDF document text
    • http://wolfroccatiassociati.it/userfiles/files/38706953708.pdfIn PDF document text
    • http://rracc.com/file_media/file_image/file/16246503120.pdfIn PDF document text
    • http://jnmindia.com/outscapes/admin/ckeditor/uploads/ck/files/sogapotosa.pdfIn PDF document text
    • http://3gr-group-com.gbintl.com/ci/userfiles/files/digox.pdfIn PDF document text
    • http://teraval.cz/res/file/zaforevikuraligotod.pdfIn PDF document text
    • http://globalroomplus.com/bot/ckfinder/uf/files/71496715740.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/af704b58a8ed1621b03908dd276e3bd9/xedagilidito.pdfIn PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/91704536289.pdfIn PDF document text
    • http://www.aamuhsv-madisonalumni.org/files/files/wopunofabetanavewebolo.pdfIn PDF document text
    • https://delphin-bau.com/ckfinder/upload/files/lamorisululatugebut.pdfIn PDF document text
    • http://np-laser.com/upload_fck/file/2021-9-3/20210903161727289819.pdfIn PDF document text
    • http://kpotplace.com/uploads/files/xavonokejoluzolafonobepuw.pdfIn PDF document text
    • http://saraiaser.nl/userfiles/file/xadeximibel.pdfIn PDF document text
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/198625687038ca16b4287e6f581f9b9e/duvututotikukelitepeposij.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/55662377620.pdfIn PDF document text
    • https://alhasooncorp.com/Files/files/xaworuxotobuferapafivupuv.pdfIn PDF document text
    • https://voziky-paletove.cz/mctree.cz/pictures/other/files/pafuganivuzobawide.pdfIn PDF document text
    • https://parklanehotel.asia/userfiles/file/noburitikulip.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=download+hack+plants+vs+zombiesPDF 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_off0000c948.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC948 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e15a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE15A 17412 bytes
SHA-256: 1ccbb198a22ec79a931a5710d6c296437415a52648d046837954e6ae1a786a30
font_02_sfnt_off00010e1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E1F 11124 bytes
SHA-256: 10475d5d60bc212dc1ac054216238f5bd69aecc8847b62b1a0780108f211b784