Malicious PDF — malware analysis report

Static analysis result for SHA-256 0f51a2dbf48b7a84…

MALICIOUS

PDF

83.0 KB Created: 2021-09-21 04:43:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b4a6589e469477b1488d7968328af4f9 SHA-1: 2736178b076d0332e0ecafcd97a659025f62f62a SHA-256: 0f51a2dbf48b7a84ce977ec3566ea7c6a9a3c11bd4b17d671a98eb67ff222c3f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing numerous external links, many of which point to compromised websites or disposable hosting, indicating a link farm for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards techniques used to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://philabc.ru/uplcv?utm_term=tietz+fundamentals+of+clinical+chemistry+8th+edition+pdf
    • http://studiovalecchi.it/userfiles/files/mazuxegefatejuvovarile.pdf
    • https://oriental-kitchens.com/userfiles/files/37420651615.pdf
    • https://webaprint.be/img/file/rubomuvoniker.pdf
    • https://ensegun2.com/ckfinder/userfiles/files/76826310810.pdf
    • http://bilafafafa.com/shopadmin/upload/files/lezupezimamasujujis.pdf
    • http://wildpflanzen-planung.de/file/52605384978.pdf
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16132e63b6c8df---midinopa.pdf
    • https://milliondollardesiclub.com/upload_files/featured/files/15810994941.pdf
    • http://xaydunglenguyen.vn/upload/files/e0780a.pdf
    • http://giasuminhtam.com/Images_upload/files/37851228656.pdf
    • https://byocamacho.com/ckfinder/userfiles/files/90264254214.pdf
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/86ce7133f4523d324f0e6aa434b433bd/67321366950.pdf
    • http://aven.su/userfiles/file/23598380642.pdf
    • http://stl-hk.net/userfiles/44296353766.pdf
    • http://123flower.doweb.kr/upload/files/41328787597.pdf
    • http://etcpremium.com/userfiles/files/xenuxalitu.pdf
    • https://beruanglucu.com/contents/files/damogitowamewukale.pdf
    • https://marbeyoyun.com/calisma2/files/uploads/27970312658.pdf
    • https://webmenuplus.com/images/file/5155447391.pdf
    • http://pololanna.com/user_img/files/33570583852.pdf
    • https://www.profiemg.cz/upload/ck/files/72799850145.pdf
    • http://archi-m.ru/userfiles/file/nerebujeze.pdf
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/0kv55sng04mhujdfe546o7r2i0/26512769176.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dbad.bin
19930a6deb7bea42fb1c5450de478e90898dfb9f611cf190476dffc83da77eff
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBAD 18144 bytes
font_01_sfnt_off00010ae5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AE5 16792 bytes
font_02_sfnt_off000122fc.bin
309b1495549de4752c8c0ac697d83f79f6b19d121b187268e7828bfe812b3fac
pdf-font-stream PDF embedded font (sfnt) at offset 0x122FC 11332 bytes