Malicious PDF — malware analysis report

Static analysis result for SHA-256 531b8f03bc6ac99f…

MALICIOUS

PDF

71.4 KB Created: 2021-09-29 08:22:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9801164c4948e864b5bbef54a9bfb949 SHA-1: 94b11567c19fb44ba7ba219507867ea4aeb8fc12 SHA-256: 531b8f03bc6ac99f2fab89838fbc550efdc3ac87d666d9efedcbf14d05ec5ca7
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised WordPress upload sites and other disposable hosting domains. The embedded URLs suggest an attempt to redirect users to malicious content, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614389631e4c4---juxanem.pdf In PDF document text
    • http://aokunoil.com/ckfinder/userfiles/files/pasopodukilozimatobojepol.pdfIn PDF document text
    • https://residenciasanamaro.es/userfiles/files/mipopotidukiwidazazafin.pdfIn PDF document text
    • http://printrun.nl/userfiles/files/noludubosirojozusika.pdfIn PDF document text
    • http://brandnewgoods.net/userfiles/file/nejujasozuzunotosuliv.pdfIn PDF document text
    • https://alertsecurity.in/ckfinder/userfiles/files/93541022339.pdfIn PDF document text
    • http://smolninskayahotel.com/userfiles/file/gamapejib.pdfIn PDF document text
    • http://amexeuro.com/an3_Uploads/file/16621384873.pdfIn PDF document text
    • https://portecitadelle.portecitadelle.ca/ckfinder/userfiles/files/63556779994.pdfIn PDF document text
    • http://zopos.zohukum.com/ckfinder/userfiles/files/jusuzonejaganamodudamufoz.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614538f15dcab---fasekovudodorefonadiro.pdfIn PDF document text
    • http://jezirka-biobazeny.cz/UserFiles/File/wazemokezuguzenawasiwofuz.pdfIn PDF document text
    • https://buka.ru/sadm_files/vozowopinawevizivoju.pdfIn PDF document text
    • https://termofriz.rs/files/4646266403.pdfIn PDF document text
    • http://www.dialog-seversk.ru/jsplugins/ckfinder/userfiles/files/jegifuxuta.pdfIn PDF document text
    • http://gyarmatilovastorna.hu/userfiles/file/dimigatizuzuni.pdfIn PDF document text
    • http://hanaelectric.com/userData/board/file/rovibeb.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/63dd5ce73db9c2dbecc6b041b446d42c/1606820758.pdfIn PDF document text
    • https://aslplastic.com/ckfinder/userfiles/files/joxodukibujusotidawut.pdfIn PDF document text
    • http://tpokebar.com/uploads/files/wulule.pdfIn PDF document text
    • https://istruttorecinofilo.it/userfiles/file/99419614357.pdfIn PDF document text
    • http://kondicionery-lobnya.ru/upload_picture/file/96988519353.pdfIn PDF document text
    • https://habrit.tw/ckfinder/userfiles/files/wekobopo.pdfIn PDF document text
    • https://medicentrumnz.eu/medicentrum/files/file/denuwisuwarov.pdfIn PDF document text
    • http://kargo-box.com/uploads/files/1107926571.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=android+stop+playing+music+timerPDF 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_off0000b3ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3AD 16896 bytes
SHA-256: 8ae2801cf58033de09e7738087d4d39a1f19eea3186e51f6389f160ef8ba4864
font_01_sfnt_off0000de4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE4A 11052 bytes
SHA-256: e7bc11afb4ded65f4f19353eaed675aba9268e369707a7285ce7e8a8606acee5
font_02_sfnt_off0000f7e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7E3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1