Malicious PDF — malware analysis report

Static analysis result for SHA-256 43753bc1aa518aab…

MALICIOUS

PDF

90.2 KB Created: 2021-08-07 05:55:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 5ddb72273c479a1863b5315479cebbce SHA-1: cebcc7a6e39a390acd9245928d79bdb6d77e1849 SHA-256: 43753bc1aa518aab71a6ed1c5b29530b97caf1ef200aad2b6d31880b84260bdd
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users. The presence of a link farm pointing to multiple distinct hosts, some of which appear to be compromised CMS upload directories, further suggests a phishing or malware distribution scheme. The embedded URLs and the link farm structure are indicative of an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://jcon-aps.dk/userfiles/file/jetubazajudosiw.pdf In PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/nowifibimosavifub.pdfIn PDF document text
    • https://valleyrestoration.net/home/apf/public_html/ckfinder/userfiles/files/kofijufanu.pdfIn PDF document text
    • http://domingo.hu/ckfinder/userfiles/files/limolasatal.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/160beccf1a6525---44686020414.pdfIn PDF document text
    • http://boathousebrokerage.com/userfiles/file/gajufatojosubezud.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/57205805416.pdfIn PDF document text
    • https://hometeamcorp.com/images/usr/wuvusi.pdfIn PDF document text
    • http://acpiindia.com/userfiles/file/gunivajelusameliruja.pdfIn PDF document text
    • https://ruxthai-guesthouse-chiangmai.com/ckfinder/userfiles/files/73362533395.pdfIn PDF document text
    • https://ijaetis.org/ckfinder/userfiles/files/jekawexizafibon.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fe00757cd74---buzawadadunixona.pdfIn PDF document text
    • http://uctodane.cz/UserFiles/File/62698141431.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/51bd4268f46e9eccfda51abb02fa9ef3/gatawulomi.pdfIn PDF document text
    • https://dollarplus98.com/images/upload/files/38734677345.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c0db6e1b6e8---77353911460.pdfIn PDF document text
    • https://sokolzgierz.pl/web/uploads/files/2309772661.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160861cfd06f7e---fakiragomusuwitadopikevoz.pdfIn PDF document text
    • http://maginsaatmetal.com/resimlerfiles/basilazip.pdfIn PDF document text
    • http://senn1962reunion.com/clients/2/2f/2fc2c703930c5c120d54ce0350dd22c7/File/pokawulovuweguzijukuz.pdfIn PDF document text
    • http://train-in-japan.com/images/blog//file/mofojusek.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a20eed22c95---67146106614.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/35aa8aa2065915d0ff3b7a578c191f38/57118552052.pdfIn PDF document text
    • https://www.vek-bg.com/app/templates/js/ckfinder/userfiles/files/nijizafozovosefa.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/160a1793b22e64---sedolomagepadadawigevolux.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/d5b1c617220b5e6bb9fccd40ce16a0b6/vejabikufuwowivozol.pdfIn PDF document text
    • http://doubletroubels.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077e8408a1f5---21328792729.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+clean+the+crane+cool+mist+humidifierPDF 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_off0000fc3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC3A 10916 bytes
SHA-256: fb5949da1a507aacb2ba406f2e3a66d7ec4587521a93f58ecf9b4f8dec0edd22
font_01_sfnt_off0001154b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1154B 17372 bytes
SHA-256: 433e7d9ea0cd5b7a1e9d64cb8af4a88ff01eb2b3fd8f9b93ab826f10c6fe0f9c
font_02_sfnt_off000142b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142B7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1