Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a2089666e1cbcd9…

MALICIOUS

PDF

79.3 KB Created: 2020-12-27 18:56:28 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: afb283313169772bb03d6341b2e03a2c SHA-1: 7a6eea16545c190e5cded7ef224ad3c6aaf158c7 SHA-256: 4a2089666e1cbcd94a53f0c21e443aadef4d810cd4269337f5d57f1366652fe9
252 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF contains a large number of embedded links, many of which point to disposable hosting and redirect to known malicious infrastructure. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to exploit the user into clicking a link that leads to a phishing or malware download site. No scripts were extracted, but the PDF structure itself is designed to facilitate redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://ggtraff.ru/strik?utm_term=nda+exam+2020+answer+key+set+a In PDF document text
    • https://bigonokefexix.weebly.com/uploads/1/3/4/5/134518339/53839.pdfIn PDF document text
    • https://cdn.sqhk.co/kepebeso/dgCcwhe/word_scramble_puzzle_solver.pdfIn PDF document text
    • https://zuwadakake.weebly.com/uploads/1/3/4/6/134664894/zefekevajag-defomudodag-ruxukuwijonuwe-bifoz.pdfIn PDF document text
    • https://cdn.sqhk.co/veleviziwew/UwWukK5/homeschooling_options_for_high_schoolers.pdfIn PDF document text
    • https://dezusopivelisuk.weebly.com/uploads/1/3/4/7/134734284/8621658.pdfIn PDF document text
    • https://wevinavuligi.weebly.com/uploads/1/3/4/5/134505150/13b6b511c.pdfIn PDF document text
    • https://jopomewimedadi.weebly.com/uploads/1/3/4/4/134465277/nudijegudiredijizi.pdfIn PDF document text
    • https://nakotibuvifotog.weebly.com/uploads/1/3/4/6/134619478/2519767.pdfIn PDF document text
    • https://ruxapumuful.weebly.com/uploads/1/3/4/6/134682584/71203.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/950037de-a718-4fba-b737-711a7ff70fc0/nds_games_downloaden.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4f9aedfa-7e1e-47b7-bdbb-b6e3e935c02c/82338482033.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3c265389-9296-4f9b-8157-eb6a06ade10d/cnh_servis_arac.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/33a93433-d401-4507-9286-c7bcb781aae5/ceven_indir.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/24f40064-6e2c-4b96-bb99-7f45cad229e9/place_values_in_decimal_numbers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fba78250-95ab-4a59-8ef5-fa3e4f487029/straight_through_cable_pinout.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_off0000ef02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF02 5508 bytes
SHA-256: 2e243ecb7654f1a54d529e94a2c079943ed60b95dd7b75710196fa518fca4aa1
font_01_sfnt_off000101c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101C9 14740 bytes
SHA-256: 5df909441fe5e40ea36ec6775ef081a91098065ad7012647b1c54f82adaff057