Malicious PDF — malware analysis report

Static analysis result for SHA-256 99766d662d69a834…

MALICIOUS

PDF

80.4 KB Created: 2021-09-09 22:48:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 973b890310cc76ad7e1df4b42d949cb6 SHA-1: 8cc0ce6ba463c3e8d41e18936f326fc07e30e516 SHA-256: 99766d662d69a8342b60bbf62474e4ed5cc23ddfec0d1561f755f135bea41628
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of a link to a compromised WordPress upload directory is a significant indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 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://acutecardio.ru/sadm_files/darafeduwu.pdf In PDF document text
    • http://alompar.hu/uploads/content_files/files/1239162174.pdfIn PDF document text
    • http://optikametuje.cz/userfiles/file/71007491060.pdfIn PDF document text
    • https://dianthusindustrial.com/resimler/files/mozubupufu.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137bb1f5b6e2---2589442496.pdfIn PDF document text
    • https://ijpdua.com/contents/files/18487537645.pdfIn PDF document text
    • http://www.masozilina.sk/ckfinder/userfiles/files/47808665031.pdfIn PDF document text
    • https://xn----7sbeo1acdy3adh.xn--p1ai/userfiles/file/32531584296.pdfIn PDF document text
    • http://dija.lv/public/userfiles/file/lewavofanipujatupoj.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/e1ovl5ociecc11s5fqvpb6oq55/pemibowabapemomuten.pdfIn PDF document text
    • http://audyt.rowerowaszkola.pl/imgturysta/files/75557495711.pdfIn PDF document text
    • http://www.srijonihealinghome.com/fckimages/file/pirorojid.pdfIn PDF document text
    • https://nazragame.com/calisma2/files/uploads/93405219258.pdfIn PDF document text
    • http://sccsfz.org/upload/2021-09/84682174939.pdfIn PDF document text
    • https://aaaxxion.info/images/file/deguma.pdfIn PDF document text
    • http://limeitec.com/upfiles/editor/files/takamejegufav.pdfIn PDF document text
    • https://steklo-shik.ru/userfiles/file/82040494682.pdfIn PDF document text
    • http://sensi-leszno.pl/userfiles/file/velutaga.pdfIn PDF document text
    • https://rabudiagnostic.com/userfiles/files/95712161178.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613135be4f159---losotoxulikowolukokibijak.pdfIn PDF document text
    • https://ystechpro.com/nbloom/fckuploads/file/23949772211.pdfIn PDF document text
    • http://bookblog.kr/data/file/files/bawore.pdfIn PDF document text
    • https://nezrenpin.com/calisma2/files/uploads/58979986006.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=hack+csr+2+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_off0000d7a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7A9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000efbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFBB 17448 bytes
SHA-256: 17cc981d110ca7eeaa2a33bdc82653b1bde0769600303f8837873c292332e307
font_02_sfnt_off00011c7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C7A 10288 bytes
SHA-256: 320a72b1df7cab24943899f23e895685fd3cb9e2896a2240c84ba53e824f477c