Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5ab81020c471d5f…

MALICIOUS

PDF

88.2 KB Created: 2021-08-04 03:46:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 1e9e8357443deb43f65a7ee2da616433 SHA-1: 935aea6b9fbda8fe8dc384d5cf9b2a50da118030 SHA-256: c5ab81020c471d5f5cf0bef4c9bffcbde59207001a36dc5ac09f100548178398
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised CMS upload directories and disposable hosting, indicative of a link farm used for SEO poisoning or phishing. ClamAV detection and ML classification strongly suggest malicious intent, likely to lure users to malicious content or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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 https://privatecambodiatour.com/userfiles/file/bawux.pdf In PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ac48f3b9bae---96029352652.pdfIn PDF document text
    • https://marwaautorepair.com/nbloom/fckuploads/file/46896707459.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b4ca7b0a003---79137020376.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160d53eb3bb8e1---kuridox.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/rbuhsddgcv4thdh0ltf1hjmmv3/46682016423.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/gpolthblv45p9b36h9mkd6hv1q/97910544344.pdfIn PDF document text
    • https://zoorichi.com/temp/fckeditor/file/bosegedinexu.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/160a451187113d---14069492790.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160863ba812800---midewejorus.pdfIn PDF document text
    • https://licorne-hotel-restaurant.com/userfiles/file/35957846646.pdfIn PDF document text
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/3hoqttc6ggv4cro37e9fohifh3/nexuliva.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__60D4D9A31A7E5.pdfIn PDF document text
    • http://ewinghighclassof1963.com/clients/e/e4/e4cb61fc1babc639533983e887b7272d/File/xodujujowalonazujufo.pdfIn PDF document text
    • https://binarbaidfabrication.com/public_html/userfiles/file/23754621125.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/tevsil40fdrll054cbpkjr1cd5/77272284085.pdfIn PDF document text
    • http://huntland.hu/upload/file/75153561889.pdfIn PDF document text
    • https://cualuoihoanmy.com/uploads/userfiles/file/56042765736.pdfIn PDF document text
    • http://j1medical.com/uploaded/file/2779683303.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/e09dc4b3e055987cc736c3e03fecdecc/14273474014.pdfIn PDF document text
    • https://lexcochoralsoc.org/demo/lccs/beta/userfiles/files/44503831887.pdfIn PDF document text
    • http://ahs1968.com/clients/d/dc/dcea35c349c70fb55dca458fc6558ff6/File/vofewiwetap.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e97119a059b---jivuminizibulaxo.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f22788b7c1a---talotizafu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=revel+life+span+development+a+topical+approach+4th+editionPDF 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_off0000eef1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEF1 17672 bytes
SHA-256: 685f8e2bcfe8d03cd58288d0e0e88f2025bde2faa008ceebf8cca6eb58a518e5
font_01_sfnt_off00011dd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DD6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000135ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135ED 11076 bytes
SHA-256: c144507ae053b5cfb9dda189a7a5a0c88dba90ae3702dd54c03c6485974fb829