Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf91665335b5b482…

MALICIOUS

PDF

81.5 KB Created: 2021-09-22 16:57:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 2527995edf0806a40af19853932db066 SHA-1: ca323347014ef9a5820d6acf1389c1857738ca14 SHA-256: bf91665335b5b48292425ae2f37fc002cea08fbc5d62a99ea7ca291e616de226
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS platforms. The embedded URLs, such as 'https://cructi.ru/uplcv?utm_term=cricket+app+download+apk', are likely part of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 https://cructi.ru/uplcv?utm_term=cricket+app+download+apk PDF link annotation
    • http://capriololaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/49311900969.pdfIn PDF document text
    • http://weldingplaza.com/files/file/70579929146.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/lenavuwolekodelujat.pdfIn PDF document text
    • http://uzks.hr/upload/datoteke/zavibalipeboposuzobokewe.pdfIn PDF document text
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614b170c2f6b6---28654140766.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/161352be2aed9d---xosojokobejagawodewu.pdfIn PDF document text
    • https://noihoithanhtuan.com/media/ftp/file/negupirabiko.pdfIn PDF document text
    • http://contrast.no/ckfinder/userfiles/files/piminewudoseresaz.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/161408455d13c9---zaxanovotera.pdfIn PDF document text
    • http://jdjcnc.com/upfolder/e/files/20210907154250.pdfIn PDF document text
    • http://covina.crazyrockinsushi.com/uploads/files/manefopeminet.pdfIn PDF document text
    • http://yavuzselimvakfi.org/resimler/site/files/fujosupufamijumazap.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/041f512e25913bfae23f0c88c8c2b363/xusoxisirudulaxoputilo.pdfIn PDF document text
    • https://atavio.ru/files/file/46691206286.pdfIn PDF document text
    • https://navoloki.mebel18.com/uploads/files/masemuwaxowavosugisoba.pdfIn PDF document text
    • http://balassalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/42142182808.pdfIn PDF document text
    • https://thietbigas.net/media/files/82241871367.pdfIn PDF document text
    • https://washlounge.in/ckfinder/userfiles/files/54967244196.pdfIn PDF document text
    • http://ingmontagna.com/userfiles/files/josezapom.pdfIn PDF document text
    • http://www.protectakoteasia.com/ckfinder/userfiles/files/30459765434.pdfIn PDF document text
    • http://chixue.com/uploadfile/file/20210902055244.pdfIn PDF document text
    • http://nusratali.com/userfiles/files/54732006537.pdfIn PDF document text
    • http://szm.hu/userfiles/file/48413741505.pdfIn PDF document text
    • https://faceless.me/userfiles/files/82206607157.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_off0000d9c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9C6 17972 bytes
SHA-256: 9c761c98c755d8a9684aa29bc8d97c1661e1b1e1a4077914e0c456f5e3591ab2
font_01_sfnt_off000108cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108CD 10548 bytes
SHA-256: e96c11c22d23534c5b1e1db3d6853c677ced09713ee31de9d481d209ab2757f7
font_02_sfnt_off0001210c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1210C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1