Malicious PDF — malware analysis report

Static analysis result for SHA-256 53a0021c687b6828…

MALICIOUS

PDF

76.3 KB Created: 2021-03-28 19:51:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 7aef8ae620429d8e451a78041ce638a9 SHA-1: 7ff0ae308bb7c00f76183d50cc643ba745685665 SHA-256: 53a0021c687b682817241ff8fc81437bb1934bd8397917a4796bfacd85aeeef3
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, embedding numerous external URLs, with a primary suspicious URL pointing to `jumiwimov.ru`. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure suggests it's designed to redirect users to potentially harmful websites, possibly for phishing or malware distribution.

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://jumiwimov.ru/award?keyword=acoustic+guitar+music+theory+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4446930/normal_5fe1829c29087.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379614/normal_60571857411f8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379237/normal_6045bc5266e5c.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/salade/92429319054.pdfIn PDF document text
    • https://95fbbc11-640f-4658-acdf-6e09da746871.filesusr.com/ugd/e42ee3_933c8b2c54f04391bfcb096d1106d6bb.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/wipotegadodorek/iata_international_airport_codes_list.pdfIn PDF document text
    • https://9d50af6f-dbf7-41ba-b854-83985329a12b.filesusr.com/ugd/33c377_5b990eb941b64fcb8974702224ab09dc.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/19acabf6-b7ce-44ee-bfeb-4655dab53c59/reloading_manual.pdfIn PDF document text
    • https://fad58b31-c538-4d3f-828d-7998eec853b9.filesusr.com/ugd/7e6083_74e3e735b5cc400296719e40cb47cb58.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/fikuvine/75929311791.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9c844772-581c-4a6a-9f4a-70e31d8d2536/37848091998.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1681aeb6-9abb-4bc6-b8fb-8799d2ea88ed/53990516298.pdfIn PDF document text
    • https://s3.amazonaws.com/xamapebonijos/vexazunijewufiposok.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aa5b8391-b9bd-4401-86c4-e7fdcb1e5ff9/serial_de_windows_8.1_single_language.pdfIn PDF document text
    • https://8c4778c4-ed17-4cf1-86f9-5448e21c5c15.filesusr.com/ugd/6da380_58cab0689a8b497a9c09cfe147c021b8.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/03b29a41-f02c-4512-b047-bfe8d72bb718/noxojinikumuguvadutugikur.pdfIn PDF document text
    • https://s3.amazonaws.com/zexozavo/5_oclock_free_crack_giveaway.pdfIn PDF document text
    • https://cc0b58a5-7bf4-4b41-9cd7-d9bc0cd2cc6f.filesusr.com/ugd/6dc98b_0ca83d3624804bf18e3514694794bfd6.pdf?index=trueIn PDF document text
    • https://3edbbcf3-b5b1-446e-9630-835d38fa79e0.filesusr.com/ugd/6908d7_11094756e13247c3b4323b3a9584513d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/df6fedc2-45b5-4ba8-a571-e3453441a016/boxuviwopozalugotutimexa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a6fe7ee0-bf90-4b85-8ac8-838d7909db0f/55885612055.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_off0000ebb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBB7 5628 bytes
SHA-256: 024a8b74c835e4267328ba91db0336fc9913ac4a0bdea714716de3bfb93a81fc
font_01_sfnt_off0000febf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEBF 10884 bytes
SHA-256: 227f09f09fefaa860110a1a0ea26e26d3f362bd2c4c0bf07921e690dd529597c