Malicious PDF — malware analysis report

Static analysis result for SHA-256 28b6190e82b8c5b6…

MALICIOUS

PDF

76.5 KB Created: 2021-09-06 11:02:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 2bef38d0d9faf9b6c03704ee8bce5433 SHA-1: 4eac5dafeb664cc47577443099b9e7756b5cb298 SHA-256: 28b6190e82b8c5b68e7a7ce374709995bc8ec9bfeb36fa34082376d04e352df9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm with numerous URLs pointing to compromised CMS uploads and disposable hosting, indicating a phishing or redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to lure users to malicious sites or download further payloads. No scripts were extracted, but the structure and URL patterns are indicative of a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://reversetheclocknow.com/ckfinder/userfiles/files/sasolubixuta.pdf In PDF document text
    • https://thai-airpark.com/ckfinder/userfiles/files/kutuzosorel.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/03ed425f826497c12cf872f37953230d/xuzikonugusodunafirax.pdfIn PDF document text
    • https://flvirginia.com/wp-content/plugins/super-forms/uploads/php/files/53f797bdac1fac57359b6f9480bb4a34/budewu.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/161068d49ad063---95440197870.pdfIn PDF document text
    • https://advik.net/userfiles/file/42319179097.pdfIn PDF document text
    • http://turatabor.hu/media/72383649472.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/5516767db43d316c8b300c91508cc439/mojemoki.pdfIn PDF document text
    • https://clinicamanila.com/ckfinder/userfiles/files/juvad.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/ej0okb269dourhugfs9rpfi4u4/97043011082.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/oqh43pdsehte9d5jem2piocfia/68859474252.pdfIn PDF document text
    • http://xiangzhuan.tw/upload/files/kukumogori.pdfIn PDF document text
    • http://ankaser.com/userfiles/file/98319531660.pdfIn PDF document text
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/88f0d5e88d77c0403f52806ca62fa07e/99446742273.pdfIn PDF document text
    • http://broadviewlibrary.org/uploaded_bvlib/file/bonalerakakoputakuseraw.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0e066e879---renodado.pdfIn PDF document text
    • https://semagro-msw.ru/pics/images/file/54876775922.pdfIn PDF document text
    • https://proxus.nl/file/61167990274.pdfIn PDF document text
    • https://tonycustomtailoring.com/nbloom/fckuploads/file/fetemimuzumeniwitudetixa.pdfIn PDF document text
    • http://wahluenfty.com/userfiles/64966236403.pdfIn PDF document text
    • https://www.qlsny.com/wp-content/plugins/super-forms/uploads/php/files/24e94e27aff2648f471555a46d452206/modaxekewo.pdfIn PDF document text
    • http://distributoram.com/files/file/tuvoluxadefovog.pdfIn PDF document text
    • http://futuralagoparking.eu/userfiles/files/51999442631.pdfIn PDF document text
    • https://performanshost.com/calisma2/files/uploads/78713531942.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/160b5a58b97554---265614604.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=public+opinion+quarterly+pdfPDF link annotation
    • 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_off0000c4f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4F7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD0E 10944 bytes
SHA-256: cfb5520c99f30056538af617f91ea1e16cfac3833dffd10d5169253f6ea38762
font_02_sfnt_off0000f620.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF620 17632 bytes
SHA-256: f1857713a9798c636d64519aa8f02eafcec764301bb6703bcc3783d1e5d627c0