Malicious PDF — malware analysis report

Static analysis result for SHA-256 81656f350a617658…

MALICIOUS

PDF

85.4 KB Created: 2021-06-05 09:02:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 1cc0fcaa8d158403edd1c805e344721f SHA-1: abc6d7b29090ea362520c52642e94d3e8890babd SHA-256: 81656f350a617658fca0419c66b370c57193b78c76fb629fad8111cb0c97fc05
194 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 and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://nomylo.ru/pbw?utm_term=ematic+at103b+digital+converter+box+update PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4485705/normal_6012269863d24.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417815/normal_6036791384d2f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4493876/normal_6039469cc1aa7.pdfIn PDF document text
    • https://jerepukiw.weebly.com/uploads/1/3/2/6/132681878/dipelesisoxuzifebir.pdfIn PDF document text
    • https://dojulukasinu.weebly.com/uploads/1/3/0/7/130776790/kelazojar.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4381762/normal_600fbc02150cf.pdfIn PDF document text
    • https://weritudasokapo.weebly.com/uploads/1/3/4/4/134494226/jizisiduniribiveb.pdfIn PDF document text
    • https://tediresul.weebly.com/uploads/1/3/5/3/135345321/10b506e6adb9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370309/normal_5fe958e975d20.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451753/normal_6037b9e5f3c5e.pdfIn PDF document text
    • https://ximilebikunupi.weebly.com/uploads/1/3/4/8/134875253/a02a2.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4422385/normal_5fcb23eb47a1c.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/88419267-1f88-4806-9ce5-fd706e45ea78/what_is_the_best_build_for_nightblade.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/493dc2bd-e0a6-487c-9e2f-ef190e2ed5e2/samsung_rf4287hars_xaa_reset.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/08d620e4-73a0-4d59-b5c4-7c0951662632/how_to_train_your_dragon_season_1_cast.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7bfabfbc-55b1-48f4-b2a8-fe72e313056d/suzefufijefewu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2f34dd94-cac8-4c76-8294-3bb578410d71/the_vampire_lestat_book_cover.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f4570905-e69c-48f9-a592-27822cf07c67/armor_of_god_prayer_images.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/18cea2ea-91ad-4417-8175-7f6088d224ab/bikigexevugamavugu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/983fb079-f4e5-4f55-b905-e6d49f15678b/eheim_2217_canister_filter_price.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_off00010d5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D5C 5800 bytes
SHA-256: 1fe66d2e205947683f0c4b69352d6af979aa14380abd3eb96e6f3418a11ac0bd
font_01_sfnt_off0001210c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1210C 11408 bytes
SHA-256: a31035426bac00cc9a97029607c630432d0103bad062bc76354d5cf21cfb880d