Malicious PDF — malware analysis report

Static analysis result for SHA-256 a25bfd021998e09d…

MALICIOUS

PDF

84.8 KB Created: 2021-03-21 06:43:37 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 2743f88283a3243e0c7d0133da5e6dda SHA-1: de805910b17fc32bf6763fd982868d2ad17e2c0b SHA-256: a25bfd021998e09d3de3006bead88f58080a4308f1711998e485096137febb54
244 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by multiple heuristics and a machine learning classifier. It contains a large number of embedded links, with at least one pointing to known malicious redirector infrastructure. The document body, though heavily obfuscated, appears to contain keywords related to downloading PDF files, suggesting a lure for users seeking specific content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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.
  • 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://crophysi.ru/award?keyword=eenadu+epaper+andhra+pradesh+today+pdf+download In PDF document text
    • http://accueilcmb.com/83767438665755xe.pdfIn PDF document text
    • http://gatigade.iblogger.org/86951483294.pdfIn PDF document text
    • http://digitaloffice24.ru/sex_magick_documentaryks9z2.pdfIn PDF document text
    • http://internet-babki.ru/races_warcraft_3_mods08a1.pdfIn PDF document text
    • http://freud.icu/fetiwemudib1slni.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/tamobalasu/prodigy_autocode_test_strips_walgreens.pdfIn PDF document text
    • https://76c9fb28-c10e-4950-85be-37de24a2ede8.filesusr.com/ugd/fa32a6_a814149b1f1f41bca1fdf9779c549ec9.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/29909d03-625a-4746-b36f-bec4f9067512/40784749418.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/563a61ff-953a-4144-9c66-b00dac4c3dbc/power_pressure_cooker_error.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4b04634d-0075-427f-ab2d-eb98e8d3bd62/how_to_reset_kenmore_freezer_after_power_outage.pdfIn PDF document text
    • https://s3.amazonaws.com/xeruxaxer/lettre_justificatif_de_domicile.pdfIn PDF document text
    • https://s3.amazonaws.com/bidurudilidujug/weather_report_antioch_ca.pdfIn PDF document text
    • https://9e269ae7-c3cf-4b9f-bde2-1d9be064b7bf.filesusr.com/ugd/139869_066fb87dbd02464aa772ee5cf0686540.pdf?index=trueIn PDF document text
    • https://f7f2eb1f-4ce6-40bf-b337-6bcc2c9c1a95.filesusr.com/ugd/dc6899_a36b7b3a1f4d409e83c4e815c715ed9b.pdf?index=trueIn PDF document text
    • https://07f52280-50dc-49c2-beec-a2e30bf849d0.filesusr.com/ugd/7b8f90_684dc6f13fa5402797ff8903e74eb6e8.pdf?index=trueIn PDF document text
    • https://76c9fb28-c10e-4950-85be-37de24a2ede8.filesusr.com/ugd/fa32a6_09a6547a0d0f45a0b52098a35c559ef2.pdf?index=trueIn PDF document text
    • https://eecb1da5-82b7-48ef-90e5-6a20895c07e7.filesusr.com/ugd/88a84f_c395a592a36342268f8879c396f26477.pdf?index=trueIn PDF document text
    • http://memajale.epizy.com/numedusirepel.pdfIn PDF document text
    • https://8c285b57-3156-47ce-881b-df665acc117b.filesusr.com/ugd/8d46c2_37a1328b1a6b4de59ed28dcb04822e2b.pdf?index=trueIn PDF document text
    • https://71a0d42b-91d5-4e94-9338-ff69ca8a624b.filesusr.com/ugd/e5d5e5_6fdd503ae21a4354bdb071578f0b3870.pdf?index=trueIn 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_off00010d56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D56 5280 bytes
SHA-256: ce4de53447c7fd0054b50cdfcb42cbe457b2c97ef622b1b16c0b558c73b9520c
font_01_sfnt_off00011f61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F61 11964 bytes
SHA-256: c0b0f877f669776bed94aa5b08b01216b2c57b489c471e2251465b6476effb09