Malicious PDF — malware analysis report

Static analysis result for SHA-256 0553a839dd6c6464…

MALICIOUS

PDF

70.8 KB Created: 2021-05-02 06:52:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: ba19ca83999acf938482c696fd9e48a4 SHA-1: 252e61dfdcda1eaa311fe4ad74010d7e854a1119 SHA-256: 0553a839dd6c646444a8a110e6a8fae173287d4ec9247bbe7ffa8c86fe5d6467
186 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to disposable domains, suggesting a link farm or phishing operation. The primary malicious URL identified is https://midufefew.ru/strik, which is likely used to host a malicious payload or redirect to a phishing page. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://midufefew.ru/strik?utm_term=arby%2527s+secret+menu+meat+mountain PDF link annotation
    • https://fusidefedarej.weebly.com/uploads/1/3/4/8/134857834/puvinutobopawopak.pdfIn PDF document text
    • https://vozunekoba.weebly.com/uploads/1/3/4/9/134902797/xelubanafamifesi.pdfIn PDF document text
    • http://jsexj.fun/rijodamixiwajafawosalq8rqg.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411701/normal_5fdaf4b557633.pdfIn PDF document text
    • http://mon-cmbretagne.best/juzifalepasazef1vt4o.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393485/normal_602f567114fec.pdfIn PDF document text
    • https://resodarapasak.weebly.com/uploads/1/3/4/6/134659305/37d83d1dbdfb14.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485308/normal_6038b5b53914b.pdfIn PDF document text
    • http://policyhelpcenter.com/88155566554l7qi5.pdfIn PDF document text
    • http://kernig.pro/fatinoxfp5.pdfIn PDF document text
    • https://nogomikosisodop.weebly.com/uploads/1/3/2/6/132681488/7b5b4bd4.pdfIn PDF document text
    • https://luxiwejewukon.weebly.com/uploads/1/3/0/7/130738755/3a044b1e22a62.pdfIn PDF document text
    • https://fejovixojik.weebly.com/uploads/1/3/4/3/134333762/xevemalideroxeb.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4368240/normal_5ff51bc52376d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4456420/normal_6044775db5136.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4444649/normal_600751c210ce3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454820/normal_6019a81ac472d.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/aab6beca-24d9-4b36-bd6b-0acddd101d31/food_safety_class_mn.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/74d5248a-42bf-48bc-af63-8a41fd85b4a0/lididejexuzilujitusariz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/13979e49-fca4-49ab-b89d-18ad683771ca/82601185082.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/89933603-c0d8-44d9-834d-8d083858250a/fifasolikazojujisaxinulu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3b5b179c-526d-4a67-bcb5-6d156dd4263e/romatefapiminofetox.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_off0000d664.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD664 5180 bytes
SHA-256: 8b3b7f4d1e4ed3e797e1b985c29b40c89a17d6ecb84627150f856f03ae355122
font_01_sfnt_off0000e7f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7F7 11188 bytes
SHA-256: 61a9add0a5a0e0fd5883253193e3e567e9a10e6073838cd948c1376f3a791a43