Malicious PDF — malware analysis report

Static analysis result for SHA-256 112230b941fb8b68…

MALICIOUS

PDF

83.1 KB Created: 2021-09-22 18:52:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 7252e207bfe9fe65ded5c396d9f42947 SHA-1: 63498fc0cf9f06b19c031db2e33be85772ed368b SHA-256: 112230b941fb8b686d10a807d96d1a88923db5cfc98aad93d0aaf3933772ed86
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised WordPress sites, likely serving as a link farm to obscure the ultimate destination. One URL specifically mentions 'install unknown apk', indicating a malicious intent to trick users into downloading potentially harmful Android applications. The ML classifier and ClamAV detection strongly support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/3efa824c593e246e9023de23f4f3d593/jisegologuvotepipurewesu.pdf In PDF document text
    • http://dentalweek.eu/userfiles/files/juzoteto.pdfIn PDF document text
    • http://hotelborgodeipoeti.com/userfiles/files/8260502210.pdfIn PDF document text
    • http://peter-scherer.de/userfiles/file/86459161816.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16133976c9110d---25152012580.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/249272c7de7a5ea500f4f64cc1518db5/70699069301.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161434b9cf0df3---58428537606.pdfIn PDF document text
    • https://defi128.com/userfiles/files/5758247734.pdfIn PDF document text
    • http://beiks.info/public/file/nadosikififovasewi.pdfIn PDF document text
    • http://rainternacional.com/userfiles/file/xanulurisoviribad.pdfIn PDF document text
    • https://gadapavimenti.com/GadaFiles/file/joposolukasowojit.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/d9269fead9b9ea1ed92d656a0390413f/ruzexudimoraxak.pdfIn PDF document text
    • http://carzip.biz/files/uploads/files/vodewetodik.pdfIn PDF document text
    • https://vendax.ro/files/file/lalimamalikajubep.pdfIn PDF document text
    • http://isvpro.com/custom/files/sofizubazolemonepoja.pdfIn PDF document text
    • http://www.oteliapelsin.ru/ckfinder/userfiles/files/80053486026.pdfIn PDF document text
    • http://tw-echen.com/uploads/files/202109060750496451.pdfIn PDF document text
    • http://lso-msm.fr/userfiles/file/38713460572.pdfIn PDF document text
    • https://timminsrenovations.ca/file/6QbFizisfdTza93G.pdfIn PDF document text
    • https://audreyheselmans.com/_files/file/5569209200.pdfIn PDF document text
    • https://digicpictures.com/downloads/11126794367.pdfIn PDF document text
    • http://studiopassarotti.it/userfiles/files/rudamemow.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/7ac07cef70a855004e717a278950595c/29702849418.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/34414358811.pdfIn PDF document text
    • http://kiiga.ru/userfiles/file/kewosumerunolog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=install+unknown+apkPDF 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_off0000da85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA85 20568 bytes
SHA-256: 076db73221d6e3a6ee54e3f38cd446d456ce59cd84ca339a975cbe5fa450df5d
font_01_sfnt_off00010f73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F73 10148 bytes
SHA-256: 4cd54af0ece046e65f9bdc087913ef85c226a72d270616fdbd99c5a049d87f9b
font_02_sfnt_off00012663.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12663 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1