Malicious PDF — malware analysis report

Static analysis result for SHA-256 581699f4b1353444…

MALICIOUS

PDF

75.5 KB Created: 2021-09-19 09:00:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1884074925238c90df0878ca177b26d9 SHA-1: d12de89d3dd3a1eb1161e7e009f7ed3b71129be0 SHA-256: 581699f4b13534445c8da56aee17638441dceb29cdbdec648e8572cd2908f7fa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of links, many of which point to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://aapltd.net/userfiles/file/92150872589.pdf In PDF document text
    • http://unionnutritech.com/upload/files/79513736440.pdfIn PDF document text
    • http://avon-bratislava.sk/files/files/milipemad.pdfIn PDF document text
    • http://zvaracskaskola.eu/editor_uploads/system/files/bitowuroxevorokovokixug.pdfIn PDF document text
    • https://infrapanel-alegjobbfutes.hu/userfiles/file/kebelikefalaxalalinifom.pdfIn PDF document text
    • http://krupongs.com/images/file/gewewulozidorodofa.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613332aa0fb8a---94101839561.pdfIn PDF document text
    • http://naturalwonders.com/uploads/files/39430701261.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16130b456b599c---69709289583.pdfIn PDF document text
    • https://ckmusicdesign.nl/userfiles/file/27738553837.pdfIn PDF document text
    • http://china-engine.net/ckfinder/userfiles/files/49913808261.pdfIn PDF document text
    • http://kledingindex.nl/images/uploads/tiravorawexixa.pdfIn PDF document text
    • http://bbhshipyard.com/userfiles/file/96696446570.pdfIn PDF document text
    • http://iktoktatas.hu/files/file/88224653624.pdfIn PDF document text
    • https://www.premiumtrade.ro/ckfinder/userfiles/files/77071817925.pdfIn PDF document text
    • http://cattaneoarchitetti.it/userfiles/files/44493123298.pdfIn PDF document text
    • http://jubileejec.com/userfiles/files/46744276505.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161411eaebf76f---fofemetipuvoxi.pdfIn PDF document text
    • https://chandrakantmusicacademy.org/ckfinder/userfiles/files/bolibur.pdfIn PDF document text
    • http://reedxtrainternational.com/uploads/pages/file/38736832458.pdfIn PDF document text
    • http://cs-web-design.de/ablage/userfiles/files/54712340681.pdfIn PDF document text
    • https://casabresciani.it/uploads/file/85596083550.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/c022c16b5ff6d93b7164ee340f6398ea/81832901184.pdfIn PDF document text
    • http://baschin-heizung.de/meineBilderAlbertGrundschule/file/79446111584.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=russian+army+insigniaPDF 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_off0000be15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE15 19940 bytes
SHA-256: c3b48ab953ddc05cb90eda3e8559529443b5c3caac9db7df057e11fd22400117
font_01_sfnt_off0000f1af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1AF 10316 bytes
SHA-256: ed7fac90b81793827e4130657b70c8fac424c3ff904f371a411ce5bd3a359965
font_02_sfnt_off000108e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1