Malicious PDF — malware analysis report

Static analysis result for SHA-256 c838791977096a32…

MALICIOUS

PDF

80.4 KB Created: 2021-02-23 08:25:40 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: bbc4431459e02e002ff4af9189968623 SHA-1: 5a52f2d15c3f74930bc7010a5d0e9e5f67d3e366 SHA-256: c838791977096a3226252bd9e6931d17d4a895a6ad5c7bb5b69270b6b25f0052
184 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm and routes users through malicious redirector infrastructure. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than 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.
  • 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://yafferge.ru/123?utm_term=introduction+to+mechatronic+design+pdf In PDF document text
    • http://instapriz.website/10806012717say7m.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4459621/normal_5feb7628710c5.pdfIn PDF document text
    • http://salonlabs.xyz/555674915145m3yp.pdfIn PDF document text
    • http://raifaisentapp.online/dezopagibife841zw.pdfIn PDF document text
    • http://reduslimitaly.website/tosisawukiguvire3zeyx.pdfIn PDF document text
    • http://freshka.fun/22809860591rjqwz.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4414334/normal_5fcbe6873ae5f.pdfIn PDF document text
    • http://spain50off.info/-ne7v3.pdfIn PDF document text
    • https://cdn.sqhk.co/kofelejezem/bijjiha/super_nintendo_entertainment_system_games_included.pdfIn PDF document text
    • https://cdn.sqhk.co/vugasoveg/jgchfBW/15996798962.pdfIn PDF document text
    • http://vosusapar.22web.org/descent_of_man_tc_boyle.pdfIn PDF document text
    • http://lnstagram-helps-contact.com/21882933916rroyf.pdfIn PDF document text
    • http://ejinaya.com/80926303753uj2qy.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://pogewukabuk.epizy.com/ghibli_piano_sheet.pdfIn PDF document text
    • http://tabikobi.epizy.com/annamacharya_tamil_movie_free.pdfIn PDF document text
    • http://nuwixunosozi.epizy.com/what_god_said_to_pisces.pdfIn PDF document text
    • http://wuduzukatej.epizy.com/ap_literature_sample_practice_test_2_answers.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f771.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF771 5476 bytes
SHA-256: c18a8f298ceb44262a1d2cc9da8fe10a330e3702dd954c56abc47566223703d3
font_01_sfnt_off000109de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109DE 14376 bytes
SHA-256: cc90a1acf79c9f8a6aed0762a2c1148a1682f524091752e75e46fb1f111df49d