Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1c57b2773c6403f…

MALICIOUS

PDF

74.0 KB Created: 2021-02-22 00:18:26 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: b9571dd9230a8e85e4976be6019aa53f SHA-1: d2f99748c268e987a28a6f4ab8c1975f8c46ce30 SHA-256: c1c57b2773c6403ff1cadf805f06eeb2d2016871817b8773da8ac6ed4a1bd8af
126 Risk Score

Malware Insights

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

The PDF document contains embedded URLs that redirect to potentially malicious domains, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'ML_NYX_PDF_MALICIOUS' heuristics. The primary URL, 'https://jacksth.ru/strik?utm_term=integer+word+problems+with+answer+key', suggests a phishing or malware distribution lure. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing attempts that leverage embedded links to deliver malicious content or redirect users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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 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/strik?utm_term=integer+word+problems+with+answer+key PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4460688/normal_5fde64e94cb5f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4475209/normal_60090a4235f8a.pdfIn PDF document text
    • https://tixanesel.weebly.com/uploads/1/3/4/2/134234664/5220569.pdfIn PDF document text
    • https://cdn.sqhk.co/repudodo/1ijjbgd/paye_pay_online_bill_pay.pdfIn PDF document text
    • https://fadefewili.weebly.com/uploads/1/3/4/3/134316521/6be56105c53a87.pdfIn PDF document text
    • https://cdn.sqhk.co/mewobonovagi/hekhjjl/zombie_roadkill_3d_mod_apk_revdl.pdfIn PDF document text
    • https://cdn.sqhk.co/rorajakura/ibhaq16/melody_thomas_scott_first_husband.pdfIn PDF document text
    • http://roman-holidays.shop/instagram_influencer_collaboration_templatezkvyd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4449990/normal_6004de7cd62e7.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4448540/normal_5fcaa3e63ae5f.pdfIn PDF document text
    • https://cdn.sqhk.co/xenivoronizu/ZNgdVig/51408413249.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393364/normal_5ff8cda1b040d.pdfIn PDF document text
    • https://kaledawuvilef.weebly.com/uploads/1/3/4/7/134727412/mekamoxi.pdfIn PDF document text
    • https://cdn.sqhk.co/legikowe/h7hfPha/58390721426.pdfIn PDF document text
    • https://takewinedol.weebly.com/uploads/1/3/4/7/134768260/dojudipusupop.pdfIn PDF document text
    • https://cdn.sqhk.co/benibavagoge/ekhdjgo/4796776033.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/babetafaperaxov/copd_treatment_guidelines_chart.pdfIn PDF document text
    • https://s3.amazonaws.com/webipejonavuv/map_vs_switchmap_android.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d58e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD58E 5496 bytes
SHA-256: b89ff13311effbe11623142eb9ab6b50133ca9a5f85a1fea49c2e7e9eb30c237
font_01_sfnt_off0000e815.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE815 10732 bytes
SHA-256: 8ea126fce36547e7310c14d43c0609043d1517332145d51d4e53952ad90c39ed
font_02_sfnt_off00010c7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C7C 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c