Malicious PDF — malware analysis report

Static analysis result for SHA-256 4837558b78bd4f5c…

MALICIOUS

PDF

70.0 KB Created: 2021-10-01 02:56:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 18f0820a8f7a4eee1e56a6761849dd50 SHA-1: 33ccbbc4f0344120fc5eafd582a6485aa234a0b4 SHA-256: 4837558b78bd4f5c159649c174e4a0a2cc2c052a297ba3654be9785a2983dc35
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file is identified as malicious by ML classifiers and ClamAV, exhibiting characteristics of a phishing lure. It contains numerous external URLs, many hosted on compromised CMS upload directories or disposable domains, suggesting an attempt to redirect users to malicious content. The heuristic PDF_IMAGE_LURE indicates the document likely presents a screenshot to obscure clickable elements, further supporting a phishing or download pretext.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 70 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://oniceh.ru/uplcv?utm_term=principles+of+highway+engineering+and+traffic+analysis+7th+edition+pdf PDF link annotation
    • http://police8coop.com/UserFiles/file/lujavosovumibelumexopiluw.pdfIn PDF document text
    • http://cafesezony.ru/fck_editor_files/files/42505634827.pdfIn PDF document text
    • http://zvaracskaskola.eu/editor_uploads/system/files/vatefiriwelerudesidefel.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/92496a8aa05c6d06a12682bd7bba98a8/tojifajexafixatuvojilob.pdfIn PDF document text
    • https://3drm.bg/uploads/pictures/files/nadaxopibamonuvesejed.pdfIn PDF document text
    • http://studiofantino.it/userfiles/files/mavabedivinikosegabu.pdfIn PDF document text
    • https://calson.garment-pro.com/ckfinder/userfiles/files/27533830352.pdfIn PDF document text
    • http://bielle-srl.com/userfiles/files/62902977975.pdfIn PDF document text
    • https://bestcaps99.com/ckfinder/userfiles/files/tuzutaganelewevapug.pdfIn PDF document text
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/zowuj.pdfIn PDF document text
    • http://songchanraccomposite.com/upload/files/ralewog.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613723af700e3---xexini.pdfIn PDF document text
    • http://fashionflutters.com/ckfinder/userfiles/files/fujoteg.pdfIn PDF document text
    • https://mimpishio2bet.net/contents/files/94619306659.pdfIn PDF document text
    • http://koopmankennedyfeller.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gidujivadoxofojoko.pdfIn PDF document text
    • https://highfieldhousehotel.net/nbloom/fckuploads/file/segufomiwejazokalefenitud.pdfIn PDF document text
    • http://mawratanews.com/armedia/uploads/files/38577935057.pdfIn PDF document text
    • http://asiavent.com/UserFiles/file///88951858444.pdfIn PDF document text
    • https://chinese-wall.tw/upload/files/43939497407.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/ovs7lvgfctv54l9qbul28vjnc4/78815494550.pdfIn PDF document text
    • http://biancoacolori.it/userfiles/files/dakak.pdfIn PDF document text
    • http://montoaneli.com/ckfinder/files/diwoget.pdfIn PDF document text
    • http://sumtinathholidays.com/admin/uploadfiles/file/tigomojosapomifu.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16150173721e6d---97846047872.pdfIn PDF document text
    • http://massvt.sk/editor_uploads/system/files/91677666261.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_off0000b42f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB42F 14324 bytes
SHA-256: adf21f93abf0ee560c1f69520a63559a207273928e932ebe4c4ea761faa240af
font_01_sfnt_off0000d7a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000efbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFBF 11148 bytes
SHA-256: cadeaf2a54ba266b89347520985e0c84e91ed7b9dec752abe572024450683fce