Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb71430f639be053…

MALICIOUS

PDF

82.8 KB Created: 2021-09-05 11:35:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0ef6ab3d5383ee2e1048df5d139a04d6 SHA-1: 493fcf970815bc99a5016943f31fd65897c4d176 SHA-256: cb71430f639be05381add6b59674e738fc670e014b67815bf416be9ac2a1b69d
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple heuristics indicating malicious intent, including random and compromised CMS upload links, and is flagged by ML and ClamAV as a phishing trojan. The embedded links point to various domains, suggesting a link farm designed to distribute malicious content or facilitate phishing. While no scripts were explicitly extracted, the nature of the links and the PDF structure strongly suggest an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 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.
  • 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 https://wastran.ru/uplcv?utm_term=python+basic+coding+pdf
    • http://www.supercarrentalsofmiami.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5363531037---sefixabagojukefunizu.pdf
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acfbd74616f---80167495551.pdf
    • https://kis-u.com/page_data/file/20210527204258.pdf
    • http://ptairsupply.com/userfiles/file/mikas.pdf
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1606d52eca2158---31728883860.pdf
    • https://kar360.com/resimler/files/41491504161.pdf
    • https://godahoian.com/app/webroot/upload/files/25679686928.pdf
    • https://bruceautoservice.com/files/file/wakaximigu.pdf
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/16088c30bc8b16---jabotebobananusifadaze.pdf
    • http://studiotecnicomancini.eu/userfiles/files/fitad.pdf
    • http://acsalma.hu/userfiles/files/13405723452.pdf
    • http://sam-global.ch/files/file/77561040812.pdf
    • http://rockhouseschool.com/rockhouse/uploads/files/75711533433.pdf
    • http://aimic.com/userfiles/file/76777066427.pdf
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611fb34080f21---41113558391.pdf
    • https://micro-churches.net/uploads/file/zevudun.pdf
    • http://artistalexanderkanevskywinnerinternationalaward.com/clientMedia/file/89840825731.pdf
    • https://plantbiochem.com/ckfinder/userfiles/files/sibewajewonigunopexanati.pdf
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/d70338202c677c62645273019f964242/921738547.pdf
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/16107a4614f5b3---nevorigope.pdf
    • https://schilderlesvakantie.nl/ckfinder/userfiles/files/89490679510.pdf
    • http://ahkjt.com/upfile/file/65381095981.pdf
    • https://leo.tw/upload/ckeditor/files/womejamemusisawu.pdf
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609a866ce188a---31814323771.pdf
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/89069b2f918e3399c55cf814c6c748e4/fobepizu.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e034.bin
e34ffe236c39b12e4cbf6195d116208838cb35c24db4206740a4313132b59735
pdf-font-stream PDF embedded font (sfnt) at offset 0xE034 16928 bytes
font_01_sfnt_off00010c88.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C88 16792 bytes
font_02_sfnt_off0001249f.bin
35a091b7302db734aeb9761ed0bbb1ce28e39bd22839739cf5bc70388f2bbf98
pdf-font-stream PDF embedded font (sfnt) at offset 0x1249F 10876 bytes