Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1a87bfddff939df…

MALICIOUS

PDF

84.2 KB Created: 2021-03-04 19:21:32 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: cc9f6fea550474759a3092f163fff950 SHA-1: 7844485da18469ec41b8f8ff31b1028fed299997 SHA-256: a1a87bfddff939dfeeacf6c452f1f57debb54cbbd1e0747c751b36414d44af0c
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains numerous external links, many pointing to disposable domains, suggesting an attempt to manipulate search engine results or distribute further malicious content. While no scripts were directly extracted, the PDF structure and external links are indicative of a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://seumenha.ru/123?utm_term=diary+of+a+wimpy+kid+double+down+free+online+book PDF link annotation
    • http://bonifacy.site/honkai_impact_3_guide_indonesiaeae04.pdfIn PDF document text
    • http://blubadgehelp.net/install_airmon-ng_di_termuxhm347.pdfIn PDF document text
    • https://cdn.sqhk.co/rorezina/EtIjd0f/tom_and_jerry_characters_name.pdfIn PDF document text
    • https://cdn.sqhk.co/raninogozo/ejbHsja/bloons_supermonkey_2_mod.pdfIn PDF document text
    • http://goldstein.berlin/eva_streaming_vostfrutp1d.pdfIn PDF document text
    • http://palitra-cveta.ru/how_to_fix_simplehuman_soap_dispensercm6jb.pdfIn PDF document text
    • https://cdn.sqhk.co/rilixuzewiv/jjjccWH/las_vegas_shows_and_events_october_2019.pdfIn PDF document text
    • https://cdn.sqhk.co/xozakatupab/f0gfihv/52268582881.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://6205d428-d5dc-494e-bbc3-e2236f9d811e.filesusr.com/ugd/6885a6_97007383c2424a4b9053cb3f86bd3fea.pdf?index=trueIn PDF document text
    • https://ff0b3df2-dc61-4aeb-9024-93fa9b5bc175.filesusr.com/ugd/aa14a9_1269357c499e453f95132569611eebd2.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/fc83991e-c6d8-4b3b-9296-3ef84876c541/fupewebulasexel.pdfIn PDF document text
    • https://s3.amazonaws.com/legenapi/chuck_season_5_full_episodes_free.pdfIn PDF document text
    • https://db244590-af71-4c33-bd6e-2f8f55f31281.filesusr.com/ugd/fdab61_d593896a50ba4a3ba4d3bdd9b2dbe638.pdf?index=trueIn PDF document text
    • https://e82ff0bd-cb1a-4782-8b92-0a0fb7657660.filesusr.com/ugd/d17951_2d9a2594ac734b0f9af54b4cadaaa1f2.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a6a3e961-1288-4668-a573-480a373f6c50/13428201549.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/837993c6-8cb5-48d0-8af2-c2392c7373a3/63788142894.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9e81b93b-2796-42dd-9917-381fa36595b8/mcsa_2016_study_material.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2327fa9b-990d-4438-8795-25ce03ecfe74/35145963018.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/108be5d2-3bd9-4e7f-9389-e93450c5f55c/75415476822.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ac161654-7caa-4a37-a07e-d44480cca499/best_solvent_for_recrystallization_of_acetaminophen.pdfIn PDF document text
    • https://s3.amazonaws.com/libosokune/62994652966.pdfIn PDF document text
    • https://s3.amazonaws.com/tejuvonixag/jigudejegige.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/54d2d32d-f7c9-425b-9fee-435d3d37e40f/89313238511.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/23f3ab21-666d-4f3e-b70e-885f48c273a8/what_is_the_4_digit_code_for_philips_tv.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_off0000fef1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEF1 5208 bytes
SHA-256: 39fcb4cecf6ae8633532240ad548de810ab6c47813056fedfc555f9c491fd257
font_01_sfnt_off0001109a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1109A 10504 bytes
SHA-256: 7899a22db767080efa1a92e71ab07b1971dc8038071357632e2748ab43b186f5
font_02_sfnt_off0001348a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1348A 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34