Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a77c88277761285…

MALICIOUS

PDF

113.2 KB Created: 2021-05-20 00:48:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 474ff01607f684a527c0645b1ae53c49 SHA-1: 2443beda7f391c068cc2786eb8972c815634b8b6 SHA-256: 6a77c88277761285324ecdfa572faf7ff1ac9c256d2cf27bdf05e46d871abb75
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, a common tactic for SEO spam or phishing campaigns. One of the extracted URLs, https://vilenefex.ru/strik, is flagged as malicious. The ClamAV detection and ML classifier also indicate malicious content, likely related to phishing or malware distribution through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://vilenefex.ru/strik?utm_term=skills+worksheet+critical+thinking+analogies+answers
    • https://cdn-cms.f-static.net/uploads/4389570/normal_606d250f8e93e.pdf
    • https://static.s123-cdn-static.com/uploads/4456712/normal_5ff77564d8b94.pdf
    • https://xipidutaz.weebly.com/uploads/1/3/4/4/134401361/22537aec566f.pdf
    • https://cdn-cms.f-static.net/uploads/4496148/normal_606b508fdb2a4.pdf
    • https://static.s123-cdn-static.com/uploads/4450047/normal_5ff71b9dd66f0.pdf
    • https://gazufasuro.weebly.com/uploads/1/3/4/4/134482956/nasiduwafas-gikerugub-kiwonabeve-momoburosesax.pdf
    • https://cdn-cms.f-static.net/uploads/4393359/normal_6021a3aeb1d3f.pdf
    • https://gizetaxawu.weebly.com/uploads/1/3/1/8/131871526/02f8079bd55f5.pdf
    • https://cdn-cms.f-static.net/uploads/4428061/normal_605a18e2a1b95.pdf
    • https://cdn-cms.f-static.net/uploads/4501501/normal_5fd95fb15fb69.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/95cce24a-f2ca-4458-98d8-b3ba591caea7/a_dance_of_dragons_audiobook.pdf
    • https://s3.amazonaws.com/popilo/73595014707.pdf
    • https://uploads.strikinglycdn.com/files/405574aa-c959-4144-8b75-2398afee3861/kellys_small_engine_repair_memphis_tn.pdf
    • https://uploads.strikinglycdn.com/files/9f94d748-98b3-469d-b1f1-8f5a7ea72c2a/ancient_world_history_syllabus.pdf
    • https://uploads.strikinglycdn.com/files/d85bb4be-aa8e-4cf6-8529-e0b42b125fba/kalufaka.pdf
    • https://uploads.strikinglycdn.com/files/f5613956-c041-43d7-b011-9dc1c7aaa1ce/14298667757.pdf
    • https://uploads.strikinglycdn.com/files/0272d132-05a9-4802-ad4c-f97ff644fa5c/what_are_the_terms_used_in_poetry.pdf
    • https://s3.amazonaws.com/wujodibu/abhimaan_movie_song_bengali.pdf
    • https://uploads.strikinglycdn.com/files/4cfa870b-9411-4f35-a7e1-d589e51adc11/vera_lite_z-wave_controller.pdf
    • https://uploads.strikinglycdn.com/files/d6ab211d-df09-448f-8610-b238fedffa55/fisafaloke.pdf
    • https://uploads.strikinglycdn.com/files/5c42b626-52b2-475d-b658-36647fee45d5/21925773387.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00017eb9.bin
022062be4d300384d01afa934a545254724e7210c0fa01ccb2fc5a3ad7037c2b
pdf-font-stream PDF embedded font (sfnt) at offset 0x17EB9 5320 bytes
font_01_sfnt_off000190e1.bin
3c1284b68b93e21dafbeff45638c3481035084a96e1bb6da6f7106a251030df3
pdf-font-stream PDF embedded font (sfnt) at offset 0x190E1 11168 bytes