Malicious PDF — malware analysis report

Static analysis result for SHA-256 a91175a0a15af588…

MALICIOUS

PDF

78.0 KB Created: 2021-04-02 19:59:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: 087c09fd5ee0c82cd8a3277d7e8923fa SHA-1: 551c6bd7724943690b222ffd5ddf8f8df2d61c0a SHA-256: a91175a0a15af588308cd9f5c3b6e5725950c31832f163a936e251255bb573d5
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://resalured.ru/award?keyword=punctuation+rules+worksheets+pdf PDF link annotation
    • https://cdn.sqhk.co/zisuzunon/gfw6Ggj/18393382412.pdfIn PDF document text
    • https://cdn.sqhk.co/sabepakofo/h4Wifje/1469306072.pdfIn PDF document text
    • https://cdn.sqhk.co/zesozote/igPWXQO/zombie_road_racing_game.pdfIn PDF document text
    • https://cdn.sqhk.co/dejojoduzi/mwhdpMw/70802377199.pdfIn PDF document text
    • https://cdn.sqhk.co/nabotogemobe/bge9ify/microsoft_onedrive_supported_file_types.pdfIn PDF document text
    • https://cdn.sqhk.co/jebanufebejo/hhJGMpX/2115852059.pdfIn PDF document text
    • http://vegofejolafud.mygamesonline.org/32494211864.pdfIn PDF document text
    • https://cdn.sqhk.co/vazodowadu/idjgG6L/bobokedobikuwajeluzowop.pdfIn PDF document text
    • https://cdn.sqhk.co/rabataxuvax/5hjhc7v/43184533124.pdfIn PDF document text
    • https://cdn.sqhk.co/pizibimo/dzFjgwB/91177397154.pdfIn PDF document text
    • https://cdn.sqhk.co/numokafas/jjdjgGA/dc_voltage_drop_formula.pdfIn PDF document text
    • http://wovoradomumakil.medianewsonline.com/allport_social_psychology.pdfIn PDF document text
    • https://cdn.sqhk.co/teduwugevoki/iejhjdX/61997774984.pdfIn PDF document text
    • https://cdn.sqhk.co/bogijifaviba/ljf9jfH/color_run_powder_games.pdfIn PDF document text
    • https://cdn.sqhk.co/pemenixa/jjjniii/64408382431.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://c809e8a6-5bdf-489d-8d8c-df4e4638a115.filesusr.com/ugd/45a296_58c1799a4c3e4823bf99ccd7a0d656a2.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/2ae1bef6-a079-4053-8b31-3e5b5b41f5c0/sm-t530_repair_firmware.pdfIn PDF document text
    • https://75a697d3-84f0-44cf-bab9-f05e37020c50.filesusr.com/ugd/7c3584_4dc2731b327b4426b6eeb0fbf5123475.pdf?index=trueIn PDF document text
    • https://89e5ed4a-33eb-42a6-b5f1-9fc07ea1e15b.filesusr.com/ugd/ff68bb_70f9f203c71f42e890e55931789e4e8b.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/2ab05d82-f04e-4e84-abec-f81c154e8640/how_do_you_service_a_mercury_4_stroke_outboard.pdfIn PDF document text
    • https://391e4f24-9fc9-4707-ac06-338edcd9f959.filesusr.com/ugd/110ef3_6681381913c940c3b1d01d3558095325.pdf?index=trueIn PDF document text
    • http://tepominofujemo.atwebpages.com/buchi_emecheta_the_new_tribe.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_off0000f180.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF180 5400 bytes
SHA-256: bcc283f38cfad1d04c0fdfab76b77e9b2d045d4e8168ea132ace83ce29451703
font_01_sfnt_off000103ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103EA 10964 bytes
SHA-256: 567db29d5d9a6b3ef248ae4751fe2dd2c14b7ee3760307cb64f60381e45563b7