Malicious PDF — malware analysis report

Static analysis result for SHA-256 524c169b1b002f73…

MALICIOUS

PDF

72.4 KB Created: 2021-06-02 01:52:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 820fa894a403109885430d94cf4a221f SHA-1: d0cb40b87572e3f572caa9260b17514b0cdea9eb SHA-256: 524c169b1b002f73687341c856d03f3783ab42d8ab23dfd5a6b7e64fdfff7227
186 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, exhibiting characteristics of a PDF link farm. It contains numerous external URIs, many pointing to disposable hosting, suggesting an attempt to manipulate search engine results or host malicious content. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a phishing or SEO spam 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://jacksth.ru/123?utm_term=beautiful+flower+vase+images PDF link annotation
    • https://jubaluwaruzazux.weebly.com/uploads/1/3/2/7/132740890/833a9346ee2.pdfIn PDF document text
    • https://kidisizim.weebly.com/uploads/1/3/4/8/134899836/kipufulikitewa-naruza-rimaxagexa-jijusitibodoxom.pdfIn PDF document text
    • https://dizegovonaziluz.weebly.com/uploads/1/3/4/8/134881707/3140500.pdfIn PDF document text
    • https://fidejilajusaxe.weebly.com/uploads/1/3/4/3/134363993/09eac969.pdfIn PDF document text
    • https://fopimakalegej.weebly.com/uploads/1/3/0/7/130738542/tawilapivuloga-jolunilo-zojukobadugi.pdfIn PDF document text
    • https://rijejoxutozi.weebly.com/uploads/1/3/4/5/134599637/bomewud.pdfIn PDF document text
    • https://suluxeposinugu.weebly.com/uploads/1/3/4/6/134634013/9783825.pdfIn PDF document text
    • https://jubonofu.weebly.com/uploads/1/3/4/2/134234671/wazuvo.pdfIn PDF document text
    • https://bosuzegenelulu.weebly.com/uploads/1/3/4/1/134131522/75b294c2306d3c.pdfIn PDF document text
    • https://gamurewum.weebly.com/uploads/1/3/4/4/134437387/6375688.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/7622dc5f-a918-4f4c-8b47-21f4b0196f04/melhor_dieta_para_homem_perder_barriga.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c675af0c-487b-405e-b574-0840eb9825df/how_to_install_nest_doorbell_on_vinyl_siding.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/580639ac-b71a-4c34-b317-d86788afad0f/busted_by_the_feds.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/97be0b75-6adf-4ee4-9053-34fcc9fd1164/60137841828.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b5982303-e36d-4ac0-9700-a009137282cf/gchq_puzzle_book_competition_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3e19fa9c-6c47-48c4-a7bb-b27ac30d475c/4877831329.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1b7d8325-25c9-4d46-92b1-a21ab5dcee8a/89674785265.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_off0000e0b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0B6 5288 bytes
SHA-256: 981c31ea94731dc616378d7f996dbf9f71c45870eeb03220bfdcdee2d9476705
font_01_sfnt_off0000f2ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2BA 9888 bytes
SHA-256: 47a3a9ee83dc34b071264c4a1ff61f1d3d509b7f2df4fe26b7cdca7ad87d4beb