Malicious PDF — malware analysis report

Static analysis result for SHA-256 d7185b8585d7cedb…

MALICIOUS

PDF

69.9 KB Created: 2021-09-28 07:32:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 8cfbd843a586fdd9ee2d1c4d41d55dbf SHA-1: ef76ce31b3c3b40528f0dba9b3175ba937bdd00d SHA-256: d7185b8585d7cedbaeff6e1fe931fcd3a422f614bb83ba03358459bf1fc870a0
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous external links, many of which point to other PDF files hosted on disposable domains, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure and numerous URLs point towards a malicious document designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://ketchas.ru/uplcv?utm_term=enlarge+keypad+on+android PDF link annotation
    • http://erainbowrealty.com/userfiles/file/22099052480.pdfIn PDF document text
    • https://total-sport.pl/img/upload/files/koxuk.pdfIn PDF document text
    • https://marjoyunlar.com/calisma2/files/uploads/mubimosekikisi.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16141d63892628---tiputunevazotakuriganode.pdfIn PDF document text
    • https://hoangvan.vn/wp-content/uploads/files/44136980228.pdfIn PDF document text
    • https://ww150001.linebot.net/upfile/files/20210908115759.pdfIn PDF document text
    • http://phongbepfagor.com/userfiles/file/37674266658.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614be41ecf2b2---61156896539.pdfIn PDF document text
    • http://veterinarioassociatopacinidallatorre.eu/userfiles/files/60789555997.pdfIn PDF document text
    • http://jjburgerut.com/uploads/files/refuragoli.pdfIn PDF document text
    • http://severstroysnab.ru/userfiles/file/mibujit.pdfIn PDF document text
    • https://noventa.cz/media/files/file/1100687716.pdfIn PDF document text
    • http://julianina.de/upload/file/86336332558.pdfIn PDF document text
    • http://isotech.si/uporabnik/file/12395686523.pdfIn PDF document text
    • https://dadesigning.com/daduserfiles/files/niron.pdfIn PDF document text
    • https://sibiucuratenie.ro/fckeditor/userfiles/file/dakuzoladebu.pdfIn PDF document text
    • http://tai-yang.tw/taiyang/upload/file/nodabekazijupaxesuxuxe.pdfIn PDF document text
    • http://mtkshop.com/images/uploads/file/33430090233.pdfIn PDF document text
    • http://gazduire-domeniu.com/UserFiles/file/29797897640.pdfIn PDF document text
    • https://groupekheidri.com/ckfinder/userfiles/files/30884893104.pdfIn PDF document text
    • http://studiocalcinoni.com/userfiles/files/54890953556.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://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_off0000b092.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB092 10488 bytes
SHA-256: cd16dc24366bb1143066560641e913359dfef3a396bc315f83defe9b8f1851b7
font_01_sfnt_off0000c839.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC839 16432 bytes
SHA-256: cc06416153f5189ad9d2974d19216d637e1d143c724c25eb6cd0355de3b080bc
font_02_sfnt_off0000f20c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF20C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1