Malicious PDF — malware analysis report

Static analysis result for SHA-256 51a5660aea51e9a2…

MALICIOUS

PDF

81.2 KB Created: 2021-09-15 13:46:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: fa0f691cbf356fb9cea622a91db97274 SHA-1: 0b8524786d9654000b6ec5deb1e1884a37bdc93f SHA-256: 51a5660aea51e9a2718de45a8393e6dfcd0d97c75400f5596fd7af345958fce9
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a phishing or malware distribution campaign. The PDF contains a high number of external links, many pointing to disposable domains, suggesting a link farm or phishing lure. While no scripts were explicitly extracted, the PDF structure and numerous external URIs indicate it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://oniceh.ru/uplcv?utm_term=which+is+easy+web+development+or+android+development PDF link annotation
    • https://selapro.com.au/application/third_party/ckfinder/userfiles/files/voxujixifetugorukumi.pdfIn PDF document text
    • http://clinicaveterinariacittadivignola.com/userfiles/files/pikopawisanimamugeja.pdfIn PDF document text
    • https://ganganagardentist.com/userfiles/file/kukivupasowad.pdfIn PDF document text
    • https://nasikampung.info/contents/files/fesavaduvawugivogumu.pdfIn PDF document text
    • http://ibnuaffan.com/ckfinder/userfiles/files/94862920728.pdfIn PDF document text
    • http://gildiamasterov.ru/userfiles/file/47063320946.pdfIn PDF document text
    • https://rajatotogroup1.com/contents/files/66219490625.pdfIn PDF document text
    • http://mtcnx.com/upload/fckimagesfile/66711352911.pdfIn PDF document text
    • http://yugreat.com/filespath/files/20210909061417.pdfIn PDF document text
    • http://sz-nuoyi.com/Upload/file/2021090901542665929.pdfIn PDF document text
    • http://tg-focus.ru/userfiles/files/dutinerutowibosuwiwazabeb.pdfIn PDF document text
    • https://mtmnetwork.net/uploadEditor/files/netodikib.pdfIn PDF document text
    • http://metabolitplus.ru/files/file/zavawofukuzafase.pdfIn PDF document text
    • http://www.astmalek.cz/obrazky/file/31235980033.pdfIn PDF document text
    • http://controlsystemco.com/cache/fck_files/file/17393395286.pdfIn PDF document text
    • https://drakbera.com/ckeditor/ckfinder/userfiles/files/39215546864.pdfIn PDF document text
    • https://www.medicalbi.com/ckfinder/userfiles/files/98857006989.pdfIn PDF document text
    • http://cerrutistudio.eu/userfiles/files/fusosijorovugomip.pdfIn PDF document text
    • http://ancient-theater.gr/media/file/mapiwejowizov.pdfIn PDF document text
    • http://sweet-sugar.de/images/uploadedimages/file/mamujux.pdfIn PDF document text
    • https://ntct.dz/ckfinder/userfiles/files/78832504179.pdfIn PDF document text
    • http://salsainkonstanz.de/media/files/pakiwo.pdfIn PDF document text
    • http://kyanite.tv/userfiles/file/kunamegujavelino.pdfIn PDF document text
    • https://t2sc.me/userfiles/50672056108.pdfIn PDF document text
    • http://kraski-chernila.ru/resources/file/52105265556.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_off0000d7bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7BB 17504 bytes
SHA-256: 3e53dbcad686c84379250e2286a75d2edd3d0fac8dfc6715ad1be9700934d739
font_01_sfnt_off000104fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104FE 11176 bytes
SHA-256: 7e6cfcfe06fcd1c94b69b03ffb427501f1c4b2a8fa48859675212d33f27d18e2
font_02_sfnt_off00011ece.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ECE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1