Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4d1a85653e62aa1…

MALICIOUS

PDF

82.9 KB Created: 2021-05-23 17:13:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 5710051d768ac96359d3bb444a752d41 SHA-1: 91e849e7d6d77843dbaf01a5697d44e438e7ec9b SHA-256: a4d1a85653e62aa1cf8eefea992f499acd05506518a0d533ca13ad6bec7d81d1
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, designed to mimic search results for specific queries. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for SEO-based phishing or malware distribution. The embedded URLs point to suspicious domains, suggesting a link farm used to drive traffic to malicious content or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://gimoguvi.ru/strik?utm_term=tabla+de+valores+normales+de+signos+vitales+por+edades+pdf PDF link annotation
    • https://widosogepe.weebly.com/uploads/1/3/3/9/133986955/xovebubi_zupiperareso_muzalavis_ziwosudeda.pdfIn PDF document text
    • https://gekawemugib.weebly.com/uploads/1/3/4/6/134623466/571bc6e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4457279/normal_60588ca539cc4.pdfIn PDF document text
    • https://puwawegolawibot.weebly.com/uploads/1/3/2/6/132682739/1156156.pdfIn PDF document text
    • https://tenefaguvij.weebly.com/uploads/1/3/4/2/134235535/warowubisufelakig.pdfIn PDF document text
    • https://niritopep.weebly.com/uploads/1/3/4/6/134634222/xenemosesilejew-vigawakok-tiwojesikoledo.pdfIn PDF document text
    • https://wivupenoremew.weebly.com/uploads/1/3/0/7/130775018/6509680.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374198/normal_603d4a3f91940.pdfIn PDF document text
    • https://demenuxukuxit.weebly.com/uploads/1/3/1/4/131438289/3229017.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411503/normal_5fd7d4ba782aa.pdfIn PDF document text
    • https://sagerogokijisoj.weebly.com/uploads/1/3/4/6/134601402/9388144.pdfIn PDF document text
    • https://wivapofeselaf.weebly.com/uploads/1/3/5/3/135317026/eafc7565c.pdfIn PDF document text
    • https://putifetoz.weebly.com/uploads/1/3/7/5/137515519/zapagod.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/seriposuj/dynamic_programming_in_computer_science.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/31442158-a483-41d2-8e69-6dbb1758fb16/chaplet_for_the_dead_rosary_prayer.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/57baf12d-f478-43dc-acfd-dbdf4c36b3ff/are_mercedes_c_class_expensive_to_fix.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/81a09379-230c-46ef-999e-5ba9ddd23424/how_do_you_use_a_devilbiss_5_liter_oxygen_concentrator.pdfIn PDF document text
    • https://s3.amazonaws.com/wexukufedepim/2014_cadillac_ats_service_manual.pdfIn PDF document text
    • https://s3.amazonaws.com/gotenukevepunin/characteristics_of_good_information_appropriateness.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fcbb68b1-1250-40e4-a0de-674385595da3/30847327184.pdfIn PDF document text
    • https://s3.amazonaws.com/lomogas/pirates_of_caribbean_game_for_android.pdfIn PDF document text
    • https://s3.amazonaws.com/mubemutolewe/convert_to_word_adobe_reader_touch.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_off000103d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103D9 5508 bytes
SHA-256: 71e42f2c3ad8df3b9b026d7723d38349857a2c1f25a17eb033a4781e1cc7ce06
font_01_sfnt_off00011684.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11684 11448 bytes
SHA-256: 1331f397570cf4f94d3875e348d93f09a3def449ee6f7a8ae010eceb4318216d