Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb88763a42ac36fe…

MALICIOUS

PDF

83.6 KB Created: 2021-03-25 17:43:03 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: d18f539e2f2b40cf66c5678ae643aceb SHA-1: 2150c5a9deb0f17af68d629f2f280de0f15e7bd1 SHA-256: cb88763a42ac36fec13d06f35b0ed1353209856e973e3f71d78ce32e98f2c99a
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of external links, many pointing to disposable hosting services, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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
  • 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://baarspo.ru/strik?utm_term=is+a+picture+more+accurate+or+mirror PDF link annotation
    • https://tiwozujipi.weebly.com/uploads/1/3/5/3/135317022/2564888.pdfIn PDF document text
    • http://pokupka.space/vezovizipezasnnn30.pdfIn PDF document text
    • http://my-favshopd.online/pencil_project_templatesx87ls.pdfIn PDF document text
    • https://lujegasot.weebly.com/uploads/1/3/0/9/130969173/ledejeg.pdfIn PDF document text
    • https://fuzewejobedogu.weebly.com/uploads/1/3/1/4/131482867/9823c481f80f7c4.pdfIn PDF document text
    • https://sekatuxu.weebly.com/uploads/1/3/4/8/134894727/7d360d53d68bad4.pdfIn PDF document text
    • https://bipawekiramobaz.weebly.com/uploads/1/3/5/3/135325031/846916.pdfIn PDF document text
    • http://noverst.xyz/jlab_air_true_wireless_earbuds_manualopoup.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/e979eb48-3a89-4811-a4ac-df6541e068d7/ruwofosojipazegudusad.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7730e550-9b24-4a7a-910b-3f7c4d2e65aa/kasutijeripurejexuwaw.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b0bb4595-4643-4ee0-bfcc-9686f2017c2c/how_to_write_a_6_paragraph_argumentative_essay.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/21710f05-418d-4706-9b4f-0dd5464c4f21/how_to_program_distech_controls_thermostat.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c26d23e9-ff0f-492f-bd5d-c33811748c36/69942112780.pdfIn PDF document text
    • https://8569cc17-8b2a-4187-ace0-95b0550b99f0.filesusr.com/ugd/d6eede_c90d6194d9b94f9a9905cf40516e57ef.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/c0c2ae9d-777b-4886-938b-75ba996b2ae8/34449483180.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eb3e52b6-e9a2-4e71-b76e-061bb81f985d/fepedigadowuxopurinuka.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7fb5866a-17d4-4346-9997-dcccffc9cca1/how_many_after_books_did_anna_todd_write.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/06b0301b-3892-40c1-8ea7-79363707fff7/how_to_get_a_replacement_ssa_1099_for_a_deceased_person.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/250f3cc3-6716-4b18-89f0-aa8fd82464b8/fender_mustang_v2_20_watt.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/91d22ef0-a32b-40b8-8951-da4dedaca5e6/57610872335.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/94f79565-287a-4e38-afb2-4078b04fd076/death_note_movie_ending_explained.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/273b8131-387c-4d54-a1c3-825e96e83147/63516224247.pdfIn PDF document text
    • https://d8d691c7-cf48-432b-bece-a54604b57851.filesusr.com/ugd/1e3a4b_b1ec8da6c8c64f31be58bb8d7ad57bd5.pdf?index=trueIn 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_off00010a43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A43 4984 bytes
SHA-256: dc5682e9d23da943252c5d75051e330815267a3f5801ec1add1a6eb026140ff5
font_01_sfnt_off00011b21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B21 10992 bytes
SHA-256: 5bf8fcb0d9800eb4833ad7cd4465021be19d7e0647ad2e33b5f3d54396614f40