Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc0f143a4b4a7bf8…

MALICIOUS

PDF

83.8 KB Created: 2021-05-12 23:10:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: a32262c0a063ccfbdef91e9bf9ea305c SHA-1: b911f68780b95dbc12fae3b1b5a614798b4e4158 SHA-256: bc0f143a4b4a7bf8985832f11a403f860760029c6e2ea2f1aa33610692f2f019
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous external links, many of which point to disposable domains and are part of a link farm strategy. The primary URL, 'https://bologen.ru/strik?utm_term=lista+de+verbos+irregulares+completa+en+ingles+pdf', suggests a lure related to English verbs, but the heuristic firings indicate a mass of external PDF links designed for SEO. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://bologen.ru/strik?utm_term=lista+de+verbos+irregulares+completa+en+ingles+pdf PDF link annotation
    • http://fashion-deals.xyz/sentry_safe_instructions_keypad5k62o.pdfIn PDF document text
    • http://nafigunagofadab.getenjoyment.net/96404392075.pdfIn PDF document text
    • https://wilalunawotepa.weebly.com/uploads/1/3/4/6/134608105/sibis.pdfIn PDF document text
    • https://wixetaduzem.weebly.com/uploads/1/3/4/4/134471786/6194788.pdfIn PDF document text
    • https://zativazu.weebly.com/uploads/1/3/4/5/134586929/xazimawumuxa.pdfIn PDF document text
    • https://mepodatadun.weebly.com/uploads/1/3/1/4/131452799/duxuxijamu.pdfIn PDF document text
    • http://physcoo.com/civil_war_timeline_worksheet_answersp16hi.pdfIn PDF document text
    • http://gadatoreneperil.mygamesonline.org/how_do_i_activate_call_waiting_on_my_panasonic_cordless_phone.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/ad7b977d-2c46-479b-8f1e-db5ea95c23eb/avid_artist_mix_euphonix_mc_mix_faceplate.pdfIn PDF document text
    • https://s3.amazonaws.com/nerugiraxura/botirur.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e3bce76a-9b69-48e5-b8ee-dc555352afbb/28136329299.pdfIn PDF document text
    • https://e60c805d-b9e1-47fc-b045-983511e9ac1f.filesusr.com/ugd/116bb2_72ae36131653462b9614048f65d30e91.pdf?index=trueIn PDF document text
    • https://e942959e-95af-4115-ab05-a6e38533eaad.filesusr.com/ugd/66f7a0_dbb1023b571f4e4690135824f2034e55.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/e9e69480-d9f3-48f0-a40e-135f567ab7aa/41458809214.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fd56c235-ed00-420b-82d1-910cf36dd9c7/29437737689.pdfIn PDF document text
    • https://s3.amazonaws.com/bibejovixapis/16026986306.pdfIn PDF document text
    • https://s3.amazonaws.com/vuzotisenixava/best_shelf_stereo_system_2017.pdfIn PDF document text
    • https://s3.amazonaws.com/lijopavexanuse/26004311814.pdfIn PDF document text
    • https://s3.amazonaws.com/kavalukato/92775417430.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f27e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF27E 5616 bytes
SHA-256: 08ec89426c1fb2ce08851458064e7485ff208cae6b20c8615916c6a3af5c5278
font_01_sfnt_off0001058d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1058D 11372 bytes
SHA-256: ca78e6ecc19412b587f872a61c2d1d46cb9a72f4e6074f19c2e21fd37e737297
font_02_sfnt_off00012aba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ABA 16060 bytes
SHA-256: d8a1a34de14a7b8fce5e51635835121d353d188f9ac9ce1e11538509fd4c5cdc