Malicious PDF — malware analysis report

Static analysis result for SHA-256 a509ac26e5699ed9…

MALICIOUS

PDF

85.5 KB Created: 2021-03-20 17:05:53 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 19346890e9b55a6357db8a4716715570 SHA-1: dd58910789cfee3926869946dfcd23f46547fa9e SHA-256: a509ac26e5699ed9c0df313bd4162ebe422a9c32a2d280b7c91aee5bdebd72a5
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. It functions as a link farm, containing numerous external links to other PDF documents, likely for SEO manipulation or to distribute further malicious content. The presence of external URIs and the link farm heuristic strongly suggest this document is part of a larger phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nipisod.ru/award?keyword=varicela+complicada+tratamiento+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4453528/normal_5feffc6cdb1e0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489441/normal_6012c183ee037.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369138/normal_604d31e3a28c6.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413983/normal_5fec05bd81c83.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://e809654a-a95b-4dbc-a338-24085255a2f8.filesusr.com/ugd/1b6cec_ed59f9a1a2124385be9180e1640ac7c1.pdf?index=trueIn PDF document text
    • https://48bd7725-9370-4d18-884e-e75d7b70c9c4.filesusr.com/ugd/f241d9_1882f6454a904177886c3101f9553cdf.pdf?index=trueIn PDF document text
    • https://12f7643e-9106-4823-89c2-0bdaecd1bc22.filesusr.com/ugd/1f6d71_855bde1d370a4752bee40ae5f05219f2.pdf?index=trueIn PDF document text
    • https://2a983b51-2e13-4971-8c1f-a5bca3ab4353.filesusr.com/ugd/e1a791_4aa773915b0648418dca2374c6216661.pdf?index=trueIn PDF document text
    • https://8ac5c8e1-9174-427d-95c2-90bebb9f105a.filesusr.com/ugd/44b221_dad1830c58a14adabcd6e19a76fa66f4.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/f567b84b-bf8d-4ef8-a9de-a2fc60ccd76e/why_is_the_red_light_flashing_on_my_insignia_tv.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4edf08b1-062c-4856-bf17-08e6110aa786/how_to_dispose_of_smoke_alarms.pdfIn PDF document text
    • https://441768bb-9839-4df4-8f78-dd1233b527f6.filesusr.com/ugd/7e6080_c9949887b47649738ce1c91e4097179b.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/753b1ba3-11fa-4dd2-be29-2dec31f55bd5/how_long_does_it_take_to_get_a_veterinary_assistant_certificate.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5ed3e336-82b5-47d1-8182-dd4c0e93e11b/how_to_score_reading_fluency.pdfIn PDF document text
    • https://50b44c92-959e-4a15-bf83-93d6b2b518d6.filesusr.com/ugd/3ed44c_c88cdefc02b441b388984b880bd944a0.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/65d734b0-669d-4287-b871-859df6953c40/what_causes_blood_spot_on_eyeball.pdfIn PDF document text
    • https://5a2ada08-5b6c-402a-b0df-3636415b461e.filesusr.com/ugd/434ae6_79097667e3ad45c580ce42388f5316df.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/3d7e1f6c-2a8a-4baa-9415-6bc97d1c176a/38388375903.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_off00010fac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FAC 5088 bytes
SHA-256: 2a2c4083a53f1265040c81b71edcd2dc597d608dfe9dd09b55f44bc162af95c3
font_01_sfnt_off000120e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120E9 11544 bytes
SHA-256: e5d59412cc64250e7c398b263018be5a3a88d07a76e899d6d71acfe00b037db8