Malicious PDF — malware analysis report

Static analysis result for SHA-256 8171dc257898bd64…

MALICIOUS

PDF

74.2 KB Created: 2021-06-12 07:02:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 4f907492f406f7b755d72051f668bbdb SHA-1: 04a075356a5922c740e1e748eb904441f3705d81 SHA-256: 8171dc257898bd647b6ec0147707342285dfa5f38c7c10ebee9fce630ac2828b
126 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous embedded URLs, with one prominent URL pointing to 'catamma.ru' and using 'ielts+model+essays+pdf' in the query string, suggesting a lure. The PDF structure and the presence of external URIs indicate an attempt to redirect the user to a potentially harmful site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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
  • 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://catamma.ru/pbw?utm_term=ielts+model+essays+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4448735/normal_6034415f31ec8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459170/normal_605686250eb6e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384152/normal_605eefa6385fe.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://poxanoralanu.pbworks.com/w/file/fetch/144426012/sepesikonotakili.pdfIn PDF document text
    • http://lopimexoxe.pbworks.com/f/15097637455.pdfIn PDF document text
    • http://liguduper.pbworks.com/f/how_to_cook_amaranth_leaves.pdfIn PDF document text
    • http://pitavumiza.pbworks.com/f/5814785432.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0ac3e7ca-0a2a-4543-8122-9a97140d95da/43691837130.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4377e1fa-f3ed-4b4d-94ba-8a3da0c2b74c/moda_media_y_mediana_para_datos_agrupados_ejercicios.pdfIn PDF document text
    • http://xiwitanul.pbworks.com/w/file/fetch/144563913/garudur.pdfIn PDF document text
    • http://zewalar.pbworks.com/w/file/fetch/144700014/how_to_make_a_face_mask_lanyard_with_snaps.pdfIn PDF document text
    • http://fixiguru.pbworks.com/w/file/fetch/144436323/pathophysiology_made_incredibly_easy_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c9e05d67-370d-478d-aa41-b908c283d733/how_to_check_out_of_excalibur_hotel.pdfIn PDF document text
    • http://gedelageke.pbworks.com/f/81195115969.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b5c04eea-457a-406c-ac0c-4f34d2d274e4/wahl_lithium_ion_duo_premium_hair_clipper_and_trimmer_kit_reviews.pdfIn PDF document text
    • http://rujuboxu.pbworks.com/w/file/fetch/144466521/alfabeto_fonetico_internacional_espaol.pdfIn PDF document text
    • http://fuxedemama.pbworks.com/f/earn_to_die_3_mod_apk_free_shopping.pdfIn PDF document text
    • http://zalonuzojeru.pbworks.com/w/file/fetch/144478449/pamaxuvibosumukudij.pdfIn PDF document text
    • http://bezawagiga.pbworks.com/w/file/fetch/144601044/dirt_devil_power_max_pet_instructions.pdfIn PDF document text
    • http://tijigika.pbworks.com/w/file/fetch/144513297/20938818219.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/16b783bc-2f5e-4bbd-887d-256e10c4bf6e/vapotebeditaxikoju.pdfIn PDF document text
    • http://nozobitativi.pbworks.com/f/zemeje.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/94c17d27-ff0c-4f03-9fb5-2d113e88060c/89060352280.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/542f42e7-1389-4f6f-a704-009f13a6914c/kitchen_aid_stand_mixer_5_qt_bowl.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/650bd794-9151-41bf-8407-859fe0a83971/honda_pilot_owners_manual_2020.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7b583d24-b091-4b9e-9299-3115400d274b/where_is_the_reset_button_on_a_hot_springs_hot_tub.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_off0000e534.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE534 5132 bytes
SHA-256: 8f9a63f6cbbd5ae01a26fa8ac810fe79f3b19d6f9c4c5099c64d2d89bb68764c
font_01_sfnt_off0000f6a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6A1 10856 bytes
SHA-256: 8eb538d4c56bc78502189f37b82bb09882f087e72fea56dbc749890f54803ccf