Malicious PDF — malware analysis report

Static analysis result for SHA-256 905da857bc4711b2…

MALICIOUS

PDF

72.1 KB Created: 2021-09-20 10:00:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8ce6bd0a1769fa90b7509029f206bdb9 SHA-1: 56b36f9b45c08226291eb57d647f68cf0ba3ff6e SHA-256: 905da857bc4711b22518e8ce182e1f9dee15023f8aec55e4b5726ea4c75946ca
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as a link farm, with many URLs pointing to potentially compromised or disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically a phishing trojan. Although no scripts were explicitly extracted, the nature of the link farm suggests an attempt to redirect users to malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://myphamlulanjina.com/upload/files/rafoxadixewetorovabu.pdf In PDF document text
    • http://1carl.com/userfiles/file/63791412948.pdfIn PDF document text
    • http://classicalgardenstatues.com/uplds/file/37478198886.pdfIn PDF document text
    • http://architectureanddesign.it/userfiles/files/69757682906.pdfIn PDF document text
    • https://laurallo.com/ckfinder/userfiles/files/86567532423.pdfIn PDF document text
    • http://www.prieteniitehnicii.ro/documente/file/21837671750.pdfIn PDF document text
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/1614091c903e9c---95572631639.pdfIn PDF document text
    • http://grandwatergatehotel.com/upfile_hotel/files/68712316604.pdfIn PDF document text
    • http://studiolegalezullo.eu/userfiles/files/14751884040.pdfIn PDF document text
    • http://sofia-es.tokyo/yamituki-n/uploads/files/93704592825.pdfIn PDF document text
    • http://amicalelaique-guyancourt.fr/ckfinder/userfiles/files/46025135422.pdfIn PDF document text
    • http://nhasachconggiao.com/luutru/files/42934927129.pdfIn PDF document text
    • http://www.amedna.com/userfiles/files/fowupedawera.pdfIn PDF document text
    • http://gddfboiler.com/uploads/files/kivugugebe.pdfIn PDF document text
    • http://farmaciafasolis.eu/userfiles/files/62212959760.pdfIn PDF document text
    • http://ecole-belair.com/ecole/file/jerekepuxuvan.pdfIn PDF document text
    • http://sp2wronki.pl/fotki/fotki/file/bolitori.pdfIn PDF document text
    • http://kingbikeonline.com/images/upload/File/lamevo.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/cb2a89d755f23218daa589d07000db7a/80953344110.pdfIn PDF document text
    • https://tivirtual.com/userfiles/file/49302484151.pdfIn PDF document text
    • http://stauarchitetti.eu/userfiles/files/kudiroza.pdfIn PDF document text
    • https://georeno.ca/userfiles/files/38341865157.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/16141ea3336342---55914789530.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=vpn+que+es+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_off0000b41f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB41F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC31 18132 bytes
SHA-256: 18aa96d8d28f4b58856b5c96a7acce98c64beab8de0b79f6edcfde2e742c5149
font_02_sfnt_off0000fb9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB9B 10456 bytes
SHA-256: 75c8c0f8ee796f7da1af1dde574a5ca179a127df5e4cc7de1dad3e9a53a30f0e