Malicious PDF — malware analysis report

Static analysis result for SHA-256 c966bf7ce93b6d26…

MALICIOUS

PDF

85.7 KB Created: 2021-07-03 07:37:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 8fe08f997d64676892484483001b9563 SHA-1: f1aabc96b96c1f3b33fffeb1a722233e9e75e4a0 SHA-256: c966bf7ce93b6d260fb16436dd35a8d324ac351befaa4a743baa5eb7cbed2278
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites utilizing vulnerable form plugins for file uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution via these links. The document body is heavily obfuscated and unreadable, preventing a more specific analysis of its lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • 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.
  • 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://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/ni6fn10blfcounsckh78fnh79j/gimoze.pdf In PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/f7547c4b2568281dd06ef723b92a2d5c/jekojojukefoz.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609234afd11f7---86441082985.pdfIn PDF document text
    • http://www.yoko-ono.be/images/userfiles/file/zasaxaferevonisevimon.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/pv418ep6kj2or2jldl2kasn2dh/lasibe.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1b33fdda84---lodezanidaduvepolu.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c759b67f2b4---sosuzomewebozodijutu.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607abc910888c---gobikeluzolodugigazo.pdfIn PDF document text
    • https://sieompaysdebray.fr/lesiom/txt/imgadmin/file/repibijimosesavurigepajip.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c2a0ab955ec---geragizedalolu.pdfIn PDF document text
    • http://martom24.pl/martom/userfiles/file/kalasetut.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609409459a3a4---fojexevodiwazisipexomizo.pdfIn PDF document text
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/adbb61fc04c774eed811fa4f51113b23/fojavidojurarixivekozi.pdfIn PDF document text
    • http://dailitara.lt/bites/uploads/file/94581132212.pdfIn PDF document text
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/c2571dc5aec2e054731bc94422c476a8/85051623090.pdfIn PDF document text
    • http://romanakladatelstvi.cz/userfiles/file/zomusujawopurimubeludule.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/ormcf8s1hdnh0kp83et5atm534/zixaxipiguko.pdfIn PDF document text
    • https://sjalikave.hu/pictures/file/34965730120.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a2783205541---5669177697.pdfIn PDF document text
    • http://pwr-tech.ru/userfiles/file/32077081176.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1608682571cb0d---27287986397.pdfIn PDF document text
    • http://domholidays.com/userfiles/file/25402823970.pdfIn PDF document text
    • https://henklinders.nl/henklinders/upload/files/baliwamamewad.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/5aa3b5oh957dkrackipd3m3i7q/961837062.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=should+mother+and+father+be+capitalizedPDF 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_off0000ec35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC35 16936 bytes
SHA-256: 60bdd6421e1e70eb816f9dd7d2d38822d380e53fbf7f38a493805954d5ce608c
font_01_sfnt_off00011811.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11811 11092 bytes
SHA-256: 4c79d60560eb25c7e06c06c9903c7f98bd28428fcc85f05bd9198e85de467395
font_02_sfnt_off00013187.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13187 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1