Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac31254b75cf90f5…

MALICIOUS

PDF

78.1 KB Created: 2021-04-09 04:43:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 2e97e28b631de8475ebf163e7b3df640 SHA-1: ccc444528febc03ff2fd0e58a8eea3923bfc62b0 SHA-256: ac31254b75cf90f513444fc54a6a1a0071d48b5ecb9b3b3732e8f33b5027c391
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which are hosted on disposable domains and appear to be part of a link farm designed to redirect users. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. The embedded URLs suggest an attempt to drive traffic to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://jacksth.ru/strik?utm_term=xiaomi+mi+band+3+rel%25C3%25B3gio+smartwatch+monitor+card%25C3%25ADaco PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4459318/normal_60004af89da15.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475203/normal_5fda3d83e3018.pdfIn PDF document text
    • http://mukinokelek.mygamesonline.org/proyecto_de_tesis_doctoral.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483361/normal_5fd98a5204d97.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414500/normal_5fe810242576d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483359/normal_5fd6e01157812.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4494432/normal_5feb7ec8d3497.pdfIn PDF document text
    • http://famozosivupiwij.sportsontheweb.net/beats_solo_2_wireless_change_battery.pdfIn PDF document text
    • http://kopogaxepaku.sportsontheweb.net/60142113379.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/3bc1691c-ea81-4b25-8d2b-76bee7961dd5/fadojafexebejajonuxopixo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a0a3e429-8af8-4908-b527-304a1e68318d/what_does_business_climate_mean.pdfIn PDF document text
    • https://ab2ac9d4-4772-4872-829d-c19fde0a4f90.filesusr.com/ugd/b919b3_cb895d7ea9ff4c45bdf439ea64ba7a0e.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a59612c8-61d2-4220-9568-71dc37ae68ac/dupidodabidum.pdfIn PDF document text
    • http://nemenarubaz.atwebpages.com/sibedijalabajux.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ed57382b-846e-4deb-98aa-c97b927e4515/the_office_scripts_us.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9255ebdc-2481-42cc-b161-6499f0fafbec/wisemi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a869869c-ab62-4a74-bfcf-00024a623af1/40621448222.pdfIn PDF document text
    • https://98cdd5c5-c43e-49eb-9373-39517e896cbb.filesusr.com/ugd/90661f_de1912a06f6c40c7a6fe28d37cc4c520.pdf?index=trueIn PDF document text
    • https://1c54689f-8f60-44d8-8d81-b144d6ea8ada.filesusr.com/ugd/787b0a_7503be6a70d646ed93e770eff672ecd7.pdf?index=trueIn PDF document text
    • https://ee897e78-a157-4eb5-8a47-d615096087a2.filesusr.com/ugd/113e89_d8df8985af034145b3d10e0a4d5c2ff8.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/b87a6375-4948-4403-986b-582f5592de7a/zegarek_mski_casio_g-shock_special_color_ga-110gb-1aer.pdfIn PDF document text
    • https://55afd15b-9a96-48ff-beb6-d705f4765584.filesusr.com/ugd/8b06a9_a8e18597f3b34c41851d2fa56a65f438.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/10294099-57c2-4d2e-a664-c8a1a60b983e/hatha_yoga_meaning.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/33fc1f7d-46c5-46fe-8900-6371b3593ef9/what_is_the_meaning_of_howling_mob.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_off0000edb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDB8 5916 bytes
SHA-256: d8300a4c38864efd8aa9e58393264bc34408a325bc626a22d6e8107c46581f9a
font_01_sfnt_off00010174.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10174 12376 bytes
SHA-256: 8a0dbfd5ca1a6d20721397030d4b45ddfe7be46df34999718118c194d40aa057