Malicious PDF — malware analysis report

Static analysis result for SHA-256 0041cb9fd13f2249…

MALICIOUS

PDF

80.9 KB Created: 2021-03-17 02:01:36 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 7a49ecec908c598093415d569817899e SHA-1: 8fb040250145d74b040b5506881063fe7ef785e8 SHA-256: 0041cb9fd13f22491afa5a70ea09cf3f8006ddfbd98bf6e2af8c61c16afc9431
186 Risk Score

Malware Insights

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

The file is a PDF identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm with numerous external URIs. The primary URL, https://kuzutuzo.ru/award?keyword=the+game+pickup+book+pdf, suggests a potential phishing or SEO manipulation tactic. While no scripts were explicitly extracted, the PDF structure and heuristic firings indicate a malicious intent to redirect users, possibly as part of a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://kuzutuzo.ru/award?keyword=the+game+pickup+book+pdf PDF link annotation
    • https://vufuredupe.weebly.com/uploads/1/3/0/7/130776381/5985109.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379035/normal_5fd19b0338419.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4385636/normal_5fd092b347f80.pdfIn PDF document text
    • https://ruwatija.weebly.com/uploads/1/3/4/8/134846771/6293942.pdfIn PDF document text
    • https://mabedokuk.weebly.com/uploads/1/3/4/5/134582143/4401709.pdfIn PDF document text
    • https://rolorizumi.weebly.com/uploads/1/3/4/3/134316308/buridi_senotadafogakam.pdfIn PDF document text
    • https://fizinizaboz.weebly.com/uploads/1/3/5/3/135304720/famusefefodo.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4418013/normal_5ff509485aeb8.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
    • https://uploads.strikinglycdn.com/files/f534d815-b3f4-4555-bb71-2c69a7c0e407/maternity_posing_guide.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/54f86063-71d0-46ba-9b3f-a2684de52e2f/single_phase_vfd_3_phase_motor.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/06efbc30-506b-4f24-bfaf-2fdb765823a6/25450837306.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7bbb7b47-7669-4044-b684-97f35b0aecb0/vabefaremaxigulu.pdfIn PDF document text
    • https://s3.amazonaws.com/juzinaramip/annual_appraisal_form_format.pdfIn PDF document text
    • https://s3.amazonaws.com/dalava/31775565679.pdfIn PDF document text
    • https://s3.amazonaws.com/jenisozazewubo/88434880593.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dc21ad80-68d2-4fdc-9ef0-d57be4762465/how_much_does_it_cost_to_replace_septic_tank_and_leach_field.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/25534961-17c7-4dfb-ba59-a6061e1b1bdb/how_to_clean_milk_frother_on_espresso_machine.pdfIn PDF document text
    • https://s3.amazonaws.com/rujimidujek/ridgid_circular_saw_rip_guide.pdfIn PDF document text
    • https://s3.amazonaws.com/wiremeresegikon/alaipayuthey_movie_bgm_music.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bf229863-8d75-417f-ace4-27bd7ec1fdb3/what_is_body_reset_diet.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_off0000ef9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF9D 5112 bytes
SHA-256: 11c0757d6f3e9ec9fe01ddc247ec32304efafe03f5831335b3472f9c99494474
font_01_sfnt_off00010104.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10104 11016 bytes
SHA-256: 1366b930bc17082862b62fef76c1b72a41bd06fa4bf57eecda3c675895302382
font_02_sfnt_off000126ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126AE 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f