Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4096a8dc010c283…

MALICIOUS

PDF

68.7 KB Created: 2021-09-29 10:45:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8ca8fa311cb30209d8c23016c728c414 SHA-1: c952c94d1d84971be30b7c4756b2f8a20be39366 SHA-256: b4096a8dc010c2839f002177a738c736a369adb08fee847b8cf5c607f4c4e208
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF file flagged by ClamAV as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS platforms. The ML classifier also strongly suggests malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • 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 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 https://infrive.ru/uplcv?utm_term=messenger+ios+apk PDF link annotation
    • http://farashimirooz.com/files/31441525495.pdfIn PDF document text
    • https://keyword-lda.pt/site/upload/file/gebizipunapuxag.pdfIn PDF document text
    • http://co-mit.com/uploads/files/24229152720.pdfIn PDF document text
    • http://ranch.pl/files/file/47566700191.pdfIn PDF document text
    • http://lienming-rubber.com/uploads/files/202109200023074308.pdfIn PDF document text
    • https://blokhol.com/upload/files/lezimutozanetezajedum.pdfIn PDF document text
    • http://dylogistics.com/userData/board/file/warasitatipesudu.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/zugumarepunemanupopemipoj.pdfIn PDF document text
    • https://pasarangroup1.com/contents/files/wimabusadanelonetob.pdfIn PDF document text
    • https://fulzugaskozpont.hu/files/rezumoxijugosanotol.pdfIn PDF document text
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/161403feebaa0f---24035203303.pdfIn PDF document text
    • http://mitcostruttori.it/userfiles/files/90036703491.pdfIn PDF document text
    • http://biolabsrl.org/userfiles/files/671180262.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/161493270f1527---92073799868.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/161353b25b2046---2858712959.pdfIn PDF document text
    • http://nasledie-sluck.by/var/upload/file/24755813570.pdfIn PDF document text
    • http://hilimall.ae/uploads/files/51198127432.pdfIn PDF document text
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16143148f59692---23916861324.pdfIn PDF document text
    • https://allcreaturesinc.com/files/files/tutimitegizeraderodatenu.pdfIn PDF document text
    • https://grandiosieventinuziali.it/filesUploads/file/76934329878.pdfIn PDF document text
    • http://tootingtaxi.com/survey/userfiles/files/67676818390.pdfIn PDF document text
    • https://kochitaxirental.com/ckfinder/userfiles/files/92571389466.pdfIn PDF document text
    • https://tranduongauto.com/app/webroot/files/images/pages/files/91066954421.pdfIn PDF document text
    • 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_off0000b19e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB19E 14364 bytes
SHA-256: 6c3f3fa97ab0526ea576dd1267f65d8876dca7e991c672162391aeee2b25949d
font_01_sfnt_off0000d595.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD595 10368 bytes
SHA-256: c4f3fcc501f854f779b25226121c7a5f09f1270a2d93e3fc5401319249779039
font_02_sfnt_off0000ed24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED24 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1