Malicious PDF — malware analysis report

Static analysis result for SHA-256 771841b704af2b93…

MALICIOUS

PDF

72.7 KB Created: 2021-09-24 17:06:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 6571f516b61389ed144ac66a49f21016 SHA-1: 410c4722a38c6c92056846fdfe324a1cf072c368 SHA-256: 771841b704af2b936c41837b717594028af4d48e1f13d2fb4ff57a164e05640c
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many of which point to compromised or disposable domains, indicating a phishing or malicious redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to lure users to malicious sites or download further payloads. The document body is unreadable, but the heuristics and URLs are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://intemhathanh.com/img_duhoc/files/56091311603.pdf In PDF document text
    • https://k31szmq42-nu28.com/contents/files/88905007837.pdfIn PDF document text
    • http://ildongwire.com/userfiles/file/91639897498.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612efc7626e2b---zamerevibopuveloburodu.pdfIn PDF document text
    • https://eseninternational.com/uploads/files/55886507807.pdfIn PDF document text
    • https://stl-log.com/htdocs/cljr/data/files/taxujugaluxeloliz.pdfIn PDF document text
    • https://magerp.org/upload/files/63741794036.pdfIn PDF document text
    • https://chasehr.in/userfiles/file/62236173767.pdfIn PDF document text
    • https://artbynela.com/uploads/file/26876735861.pdfIn PDF document text
    • http://kroonzuivel.nl/ckfinder/userfiles/files/39149856583.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/1613395f8eea2f---96617038073.pdfIn PDF document text
    • http://rana-international.com/userfiles/files/lijowegaxi.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/b508250c2408f5426970d8e702038c0e/21186235043.pdfIn PDF document text
    • http://hide-bo.com/img/tmp/file/3646803898.pdfIn PDF document text
    • https://mami-m.com/Uploads/userfiles/files/14058136555.pdfIn PDF document text
    • http://denki-shonan.com/uploadsfile/tatoruwolebomonero.pdfIn PDF document text
    • http://hillsdalehorseboarding.com/ckfinder/userfiles/files/15126591920.pdfIn PDF document text
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/0spmm9g8e4oa4psq4kem33sbdm/90234503129.pdfIn PDF document text
    • http://thietbiytedaibao.com/media/files/71823282332.pdfIn PDF document text
    • https://bevillelecomte.ovh/ckfinder/userfiles/files/11824742650.pdfIn PDF document text
    • https://jordanadams.com/ckfinder/userfiles/files/vuzawaruzekuzapip.pdfIn PDF document text
    • http://naim.naparts.com/images/fck/file/pefureguvinabeven.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=not+receiving+messages+on+androidPDF 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_off0000b71e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB71E 17964 bytes
SHA-256: 594978d91bf513e6ce5ea804c3106ea38ac4f41bcd92fb47b1606ffa50b7ef10
font_01_sfnt_off0000e45e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE45E 10712 bytes
SHA-256: f54917a666664200e1bc6aedabee7f8cea1ac22b7a94cb60609599cb273c1ca6
font_02_sfnt_off0000fccd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCCD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1