Malicious PDF — malware analysis report

Static analysis result for SHA-256 981b5a02554839cf…

MALICIOUS

PDF

85.4 KB Created: 2021-06-06 12:57:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 00a978a8db8cb5bc23e9672dda369246 SHA-1: 5946bf71603bf2541378ec050fc9ec36c31d3c5d SHA-256: 981b5a02554839cf3f4e8d4840179915fe885a8d25f88ca7719d0a94f95c19b5
126 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, identified as a link farm. One of the primary URLs, 'https://queure.ru/pbw?utm_term=cekit+electronica+basica+tomo+1+pdf', suggests a lure related to electronic books. The ML classifier strongly flagged this PDF as malicious, indicating a high probability of malicious intent behind the link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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/pbw?utm_term=cekit+electronica+basica+tomo+1+pdf PDF link annotation
    • https://kupejofep.weebly.com/uploads/1/3/4/5/134589233/3b9ef6bcc01.pdfIn PDF document text
    • https://mofuxobilewita.weebly.com/uploads/1/3/5/4/135400762/889973.pdfIn PDF document text
    • https://mokekisinuru.weebly.com/uploads/1/3/4/3/134366850/984551.pdfIn PDF document text
    • https://papozigej.weebly.com/uploads/1/3/1/8/131858530/7304316.pdfIn PDF document text
    • https://kiparefewegapip.weebly.com/uploads/1/3/2/6/132682538/8471923.pdfIn PDF document text
    • https://xuserufibizu.weebly.com/uploads/1/3/4/1/134131258/sorurabaronuxosomov.pdfIn PDF document text
    • https://xatikofaf.weebly.com/uploads/1/3/0/8/130814669/81f08576fd3af38.pdfIn PDF document text
    • https://voderixata.weebly.com/uploads/1/3/4/2/134266977/9651440.pdfIn PDF document text
    • https://vogemafebin.weebly.com/uploads/1/3/4/2/134235603/5165229.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://ximusutoj.pbworks.com/w/file/fetch/144697437/xekegixowof.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aa1787da-231b-49ba-b777-14d27b887707/gta_san_andreas_skip_mission_cheat_xbox.pdfIn PDF document text
    • http://nilanom.pbworks.com/w/file/fetch/144421179/82912538995.pdfIn PDF document text
    • http://xutosop.pbworks.com/w/file/fetch/144445866/35827159339.pdfIn PDF document text
    • http://redelaw.pbworks.com/f/percy_jackson_the_battle_of_the_labyrinth_full_book_online.pdfIn PDF document text
    • http://kapetipubi.pbworks.com/f/tazejowa.pdfIn PDF document text
    • http://visetululiv.pbworks.com/f/lovubuv.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3cc51a64-59d4-4bef-a76d-83841dd46903/molar_mass_practice_worksheet_answers.pdfIn PDF document text
    • http://jasiduvegulu.pbworks.com/f/74126389372.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8c92c787-2502-4fa0-8b3a-aa4c466a17a1/4422625837.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f9a328c9-0683-4923-9baf-c4ce842d8268/96015631264.pdfIn PDF document text
    • http://namikikis.pbworks.com/w/file/fetch/144704775/tuvukubatekuj.pdfIn PDF document text
    • http://jawegele.pbworks.com/f/what_is_the_equivalent_of_ctrl_home_on_a_mac.pdfIn PDF document text
    • http://xalomuzavege.pbworks.com/w/file/fetch/144438744/bedewok.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fbf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBF2 5368 bytes
SHA-256: 61942f56adad9186a84eb9f7771d9f58986590e03b8a5225bf0ffe9298738882
font_01_sfnt_off00010e11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E11 12864 bytes
SHA-256: bac80a5e6372e56b51602994b6e8f95af17e1500319bdb1d2af5d85c6e1058b5
font_02_sfnt_off00013782.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13782 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34