Malicious PDF — malware analysis report

Static analysis result for SHA-256 f31f52e03d335e3a…

MALICIOUS

PDF

95.4 KB Created: 2021-08-29 04:18:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 26c55605832352cbe7f396745a89d027 SHA-1: 639fde0b57371669dddca46fd99b726267a1c70a SHA-256: f31f52e03d335e3a08d25b77c8e40fe4b1406822a09ee51b3e12710a365d3af0
176 Risk Score

Malware Insights

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

The file is a PDF document flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. Heuristics indicate it functions as a callback phishing lure, prompting users to call a number for issues like billing or refunds. While no scripts were extracted, the PDF structure and embedded URLs suggest it's designed to facilitate social engineering attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9897

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://airholic.com/UpFiles/WebEditorFiles/file/guzisalap.pdf In PDF document text
    • https://atlastoursntravels.com/userfiles/file/nobegefubi.pdfIn PDF document text
    • https://binarbaidservices.com/public_html/userfiles/file/bitafawu.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160b293090bd3a---86428161125.pdfIn PDF document text
    • http://ukicda.com/admin/fckeditor_upfiles/file/2021071304302280554.pdfIn PDF document text
    • http://ruihuitax.com/files/file/fobakamenovulaw.pdfIn PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607418381195e---48667621611.pdfIn PDF document text
    • http://deccanquest.com/konadnew/userfiles/file/75018924415.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1609b21ece491a---87529520489.pdfIn PDF document text
    • http://wildpflanzen-planung.de/file/46507149949.pdfIn PDF document text
    • https://vleek.com/uploads/files/geribofa.pdfIn PDF document text
    • http://baggiez.net/userfiles/file/nowopa.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b412d8b1c21---mexodoletumelifimopat.pdfIn PDF document text
    • https://tisuputih.com/contents//files/wupuzodok.pdfIn PDF document text
    • http://canxetaidientu.com/images/file/jokubuwugejowazave.pdfIn PDF document text
    • http://jandebruijn.com/uploadimages/files/lizanoxuxuduked.pdfIn PDF document text
    • http://cjmfgxfollow.morefriendship.com/upload/files/gowikapozojoxetimepafigig.pdfIn PDF document text
    • http://originalcheck.it/public/img_admin/file///kulidorixakelaxamipe.pdfIn PDF document text
    • http://qdjshg.com/files/file/serovokatilijofevikadi.pdfIn PDF document text
    • https://cleaner.pl/userfiles/file/pidelibasezaza.pdfIn PDF document text
    • http://grafichesirio.com/userfiles/files/pupaturularajipowe.pdfIn PDF document text
    • http://jingchengs.com/jingchengs/ckfinder/files/20210801074556.pdfIn PDF document text
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/a9ecebaf5e0d047bd8de607919d9e449/64421302185.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/p1beslfudr7523t1svgvh2pqud/zujatetiwomadurefalitezow.pdfIn PDF document text
    • https://www.kasekimi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160828a478625f---81691269009.pdfIn PDF document text
    • https://mamap.in/ci/userfiles/files/xazipevofoxakubowomovepi.pdfIn PDF document text
    • http://prunay-en-yvelines.fr/ckfinder/userfiles/files/penoma.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/sdqi602a82d8qlu1ibjes9f6p1/28424829907.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=dial+up+it+servicesPDF 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_off00010b5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B5F 19676 bytes
SHA-256: f37ac73d4abae859dd682eb7be42cb368ca90688c2e541cea54cb582616667a4
font_01_sfnt_off00013ed0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13ED0 10312 bytes
SHA-256: 6bca3de869ea58eba1cdbfde576f0571d4aa152733fdf19ef78f24f9218bd56e
font_02_sfnt_off00015649.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15649 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1