Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4648ab9af7917ad…

MALICIOUS

PDF

76.1 KB Created: 2021-09-26 04:18:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 5ae81de73f39547492f102d5d1e357a4 SHA-1: 0b27cb43ae8a3ee49325fa58108389c9d4532d61 SHA-256: f4648ab9af7917ad7a7c3c3dd10c280b729d895aa7382d5c8d6a8f27b4888a46
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous external URIs and its classification as a link farm on disposable hosting strongly suggests a phishing or malware distribution campaign. Although no scripts were directly extracted, the PDF structure and embedded links are indicative of exploitation for client execution, likely leading to further malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://queure.ru/uplcv?utm_term=vpn+for+android+5 PDF link annotation
    • http://qiuyutv.com/userfiles/files/20210924101939.pdfIn PDF document text
    • http://kovofilm.cz/userfiles/file/20832126477.pdfIn PDF document text
    • http://foto-recepty.sk/images/fotky/zosajimelaje.pdfIn PDF document text
    • http://mtreurope.com/ckfinder/userfiles/files/genegexaj.pdfIn PDF document text
    • https://cs168.tw/upfiles/editor/files/31209995723.pdfIn PDF document text
    • http://nonstopsushi.com/uploads/files/wemozonasirujifixoxusawen.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/f305afda5b567aaeffec307368641eab/gozuvatawe.pdfIn PDF document text
    • https://mr-alian.com/upload/ckfinder/files/povobibufej.pdfIn PDF document text
    • http://wcsps.com.tw/ckfinder/userfiles/files/lerenezobavejajixilivir.pdfIn PDF document text
    • https://butyfarm.mm520.net/userfiles/files/rimaketa.pdfIn PDF document text
    • http://osstemcardiotec.com/files/fckeditor/file/1274518486131fe514061b.pdfIn PDF document text
    • https://dintek.eu/uploads/file/nenegobuwumesapota.pdfIn PDF document text
    • http://texinpack.com/uploadfile/file///2021090817161466.pdfIn PDF document text
    • https://2b3la571ga-70p.com/contents/files/67856272234.pdfIn PDF document text
    • http://melly-incendie.fr/img_db/91799750351.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/16138fe2b209f7---rexajozodelunovilasuveber.pdfIn PDF document text
    • http://rockpapersun.com/upload_mce_image/file/vekitonowizidex.pdfIn PDF document text
    • https://queensflower.nl/clientfiles/80184887298.pdfIn PDF document text
    • http://lachina.cn/upload/file/9348526162.pdfIn PDF document text
    • https://nomaquito-travel.com/editor-images/86666159987.pdfIn PDF document text
    • http://soeurs-scjboran.fr/soeurs/upload/files/54521270771.pdfIn PDF document text
    • https://valubil.com/public/uploads/cms_file/cms_files/sanevatopirulerirare.pdfIn PDF document text
    • 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_off0000bf09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF09 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d71b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD71B 20292 bytes
SHA-256: 6cf971dc826450be1415919eed4f976edba508efc76cc78612a19f046c3de39f
font_02_sfnt_off00010c3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C3F 10152 bytes
SHA-256: 13edcd4d0b51ff0359f19faa54bee9b3098fbf13580739021afa3565b11103a3