Malicious PDF — malware analysis report

Static analysis result for SHA-256 37690dcb2379181e…

MALICIOUS

PDF

77.7 KB Created: 2021-06-04 13:12:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1b5d7e0cd3f85b4722aa8697fb0f7377 SHA-1: 28c3787a42d03791a1c72c54d09d30ce62f03e99 SHA-256: 37690dcb2379181effd86ce12dd000c61bb5b02b418c928ecdcaefa9c11c6dbe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating it's likely a phishing or trojan delivery mechanism. The PDF contains a large number of external links, suggesting it functions as a link farm. The primary URL, 'https://oniceh.ru/pbw?utm_term=digestive+system+physiology+mcq+pdf', and the linked PDF 'https://fijozemubo.weebly.com/uploads/1/3/4/2/134234573/2339699.pdf' are key indicators of this malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://oniceh.ru/pbw?utm_term=digestive+system+physiology+mcq+pdf
    • https://fijozemubo.weebly.com/uploads/1/3/4/2/134234573/2339699.pdf
    • https://cdn-cms.f-static.net/uploads/4378623/normal_6018a0ac943c1.pdf
    • https://cdn-cms.f-static.net/uploads/4459055/normal_604014ef72b3d.pdf
    • https://static.s123-cdn-static.com/uploads/4461766/normal_5fe0fe95826c5.pdf
    • https://static.s123-cdn-static.com/uploads/4457298/normal_5fe25c7de19b7.pdf
    • https://cdn-cms.f-static.net/uploads/4420761/normal_60299012ee8eb.pdf
    • https://luzodogapop.weebly.com/uploads/1/3/4/2/134265842/govav.pdf
    • https://cdn-cms.f-static.net/uploads/4387807/normal_601d764238e4f.pdf
    • https://cdn-cms.f-static.net/uploads/4486201/normal_606d11d7befed.pdf
    • https://cdn-cms.f-static.net/uploads/4410976/normal_60540993eb8aa.pdf
    • https://static.s123-cdn-static.com/uploads/4485434/normal_5fe2add3117ec.pdf
    • https://vegirizekor.weebly.com/uploads/1/3/1/4/131407876/bokubuga_filivob_bufaf_jamajefa.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://povelin.pbworks.com/w/file/fetch/144421392/lixesirabusuzanasufosibaz.pdf
    • https://uploads.strikinglycdn.com/files/c8a8b225-69bb-4069-baf8-f075f3c4415e/52126188302.pdf
    • https://uploads.strikinglycdn.com/files/1a5ed3fa-93c1-4735-adbf-dd7fa38bec17/12v_plug_in_heater_for_side_by_side.pdf
    • http://zekodunu.pbworks.com/w/file/fetch/144584664/65135561943.pdf
    • https://uploads.strikinglycdn.com/files/fff92df2-b772-4635-af18-f17b00c82719/wimajugege.pdf
    • http://gonumutat.pbworks.com/w/file/fetch/144522189/subway_surf_apk_hile_indir_2020_apk_day.pdf
    • https://uploads.strikinglycdn.com/files/e969f5b2-b4f8-448b-9960-e57f786acc47/75206662169.pdf
    • https://uploads.strikinglycdn.com/files/9cb1461e-1043-4f4f-943a-eeb499c8ed9d/relative_clause_activity_year_4.pdf
    • https://uploads.strikinglycdn.com/files/e9870951-9698-48bb-bd1e-b230b18e4435/buzadetukegejikewada.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_off0000f28f.bin
b6affbd9f125a9ed09013faf8247ca90846400d64909a5bea4f849346397437a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF28F 5552 bytes
font_01_sfnt_off00010564.bin
74bbb9acc1e19a51979b9abd9ca0ce0a6537ce9c876cb77f066fcdd06d036c8d
pdf-font-stream PDF embedded font (sfnt) at offset 0x10564 10612 bytes