Malicious PDF — malware analysis report

Static analysis result for SHA-256 639cd55549f23a18…

MALICIOUS

PDF

84.1 KB Created: 2021-06-26 16:58:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 390e8d535b47d9a9b513bc34b9dfdcbb SHA-1: 6c6fa22b64dcb88acdb208e132a78ebd54623565 SHA-256: 639cd55549f23a185bb393925874350505d369663fcf87c362f1ce68910b27a0
156 Risk Score

Malware Insights

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

The PDF file contains numerous links pointing to other PDF files hosted on compromised websites, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple compromised CMS upload links reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8fc5ce803b---44438291140.pdf
    • http://landia-print.com/pdir/file/lelov.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606d8870da2b2---85535662248.pdf
    • https://bhsbeacon.com/FCKeditor/file/pufuforimewovuwoxawigixu.pdf
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/1ee6ce9eadbca1f06e86b6279c3e20e1/vemelademofazubos.pdf
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/26cd4b396a20523a38025ad7b401b3b0/36160894148.pdf
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b57ea21903b---texurosotulugelujir.pdf
    • https://lightspec.com/wp-content/plugins/super-forms/uploads/php/files/92f1ef75e749e8e32a8745b90e1c0c33/rimalivisuvuvezawonelobap.pdf
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b2e75644e3---4971528705.pdf
    • http://expresskaliski.info/file/49556507606.pdf
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/0e314f0ace32e6eeb446d1230f8a242a/99843476253.pdf
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/re2i7cvg2k4gtt5g2cqe85fvcm/42301549744.pdf
    • http://axiomestates.com/userfiles/file/mezifuvotu.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084d86963827---45065014535.pdf
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/jirl4tb43slju5vg5329t4ean6/10165755578.pdf
    • http://bjjiffy.com/upload/55187170669.pdf
    • https://actor-conseil.com/files/file/bukitug.pdf
    • http://tribo.kz/userfiles/File/putatobotoxugage.pdf
    • https://samudra99.com/contents//files/zunologudelojeketixewir.pdf
    • http://morard-mcf.fr/data/Files/23914093145.pdf
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/jvid9si0s9tis2ebuqjd48i3a6/72535091665.pdf
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/9d82651018c658bf833c3ae6af3fd63e/8708277246.pdf
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160c0d7e7ea0a6---68694351701.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606f46cb6dd89---dutazokajaditobelaliwazaj.pdf
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c235daef01c---zaropofaruwodimakunap.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b2bbdc83f7c---63979453194.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=future+with+present+continuous+and+be+going+to
    • 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_off0000e4d8.bin
8a7a260659672b031b65875d5dc6931a6d23fa2cc8fe789653b927727c8856c9
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4D8 17040 bytes
font_01_sfnt_off00011146.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11146 16792 bytes
font_02_sfnt_off0001295d.bin
2ddc73717113845dae817142db5128663d32882590139f2e519e469b3fedcae4
pdf-font-stream PDF embedded font (sfnt) at offset 0x1295D 11048 bytes