Malicious PDF — malware analysis report

Static analysis result for SHA-256 2c771f6311dfa9e0…

MALICIOUS

PDF

70.1 KB Created: 2021-10-12 05:19:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 3f4224101786383979bb8022a7924999 SHA-1: 063b014f7202cdbc71eb6063c430896bd8c5c6a5 SHA-256: 2c771f6311dfa9e067235273038136882056248ce6fe2686b83ca402b6a3978f
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple heuristic firings indicating malicious intent, including random and disposable link farms pointing to external PDFs. The ML classifier and ClamAV detection strongly suggest this is a malicious PDF, likely used for phishing or to download further payloads. No scripts were extracted, but the presence of external links suggests an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://cr2tek.com/userfiles/Proj_Name/files/lirozop.pdf In PDF document text
    • http://dade666.com/userfiles/202109file/2021091017181170554.pdfIn PDF document text
    • http://sztarmedia.hu/_user/file/sugojijuxikupi.pdfIn PDF document text
    • https://magnanelli.com/userfiles/file/65922856536.pdfIn PDF document text
    • https://fo-prefectures.com/pages/files/vekuko.pdfIn PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1633059081.pdfIn PDF document text
    • http://duszek-lasu.pl/userfiles/file/70446710036.pdfIn PDF document text
    • http://brno-skoleniridicu.cz/ckfinder/userfiles/files/87961838751.pdfIn PDF document text
    • http://jnmindia.com/outscapes/admin/ckeditor/uploads/ck/files/gogabugikugiwapo.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/161411d512cb1a---nufilowuzusenubitox.pdfIn PDF document text
    • http://igigeothermal.jp/userfiles/file/87772071959.pdfIn PDF document text
    • http://dominoliberec.eu/images/file/files/dijepowedu.pdfIn PDF document text
    • https://konteshamamotu.com/userfiles/file/62048018700.pdfIn PDF document text
    • http://spadhotel.com/basefile/spadhotelcom/files/bozizepupidumij.pdfIn PDF document text
    • http://ambulatorioveterinariosantanna.eu/userfiles/files/71903131383.pdfIn PDF document text
    • http://xn--2osv9pt2jfpt.com/uploadfiles/files/serugegodadewap.pdfIn PDF document text
    • http://ruizhishengwu.com/uploadfiles/file/080603084954.pdfIn PDF document text
    • http://naturabliskociebie.pl/userfiles/file/jomufikevurenovi.pdfIn PDF document text
    • http://perfect-aerosol.eu/userfiles/file/24995288115.pdfIn PDF document text
    • https://www.chablis-gautherin.com/ckfinder/userfiles/files/jirofukoru.pdfIn PDF document text
    • https://pracowniatechart.pl/fckpliki/file/83673572017.pdfIn PDF document text
    • http://fnb-concepts.com/images/uploads/files/58812117716.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/63970897623.pdfIn PDF document text
    • http://ajisushionline.com/uploads/files/majaninuviwukopamu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/HTGXzuRVGb4/uplcv?utm_term=70+dollars+into+poundsPDF 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_off0000b3cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cbe4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBE4 10428 bytes
SHA-256: 6d2df320658fdd9c83245b924ae0f9cf86b8ab1c04b844bb1ef745f4b1f5d526
font_02_sfnt_off0000e38a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE38A 15620 bytes
SHA-256: eb1487375f87326a019d5f917c4350975c3f86d1abf7e42241909e09009caf58