Malicious PDF — malware analysis report

Static analysis result for SHA-256 83d7daac539e65e2…

MALICIOUS

PDF

83.1 KB Created: 2021-06-29 10:57:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3bf592f0030082f34ea195e9d8de3fe3 SHA-1: 03ea416f53451bfa612d33cef92c4a75d80c871f SHA-256: 83d7daac539e65e2ecd064cf41f3cd91f655e88a611d8f78b849c049acb9cf91
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous embedded URLs that form a link farm, likely intended to redirect users to phishing sites or download further malware. The presence of external URI heuristics and compromised CMS upload links further supports this conclusion.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 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://catamma.ru/uplcv?utm_term=hypotension+renal+failure
    • http://sammyuriasproperties.com/userfiles/files/47608600613.pdf
    • http://bluecars.pl/userfiles/file/54848506179.pdf
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160a3e0458037f---betowavanuxevexa.pdf
    • http://zuche0551.com/upload/file/70788601498.pdf
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/jub90g79on3ae3lh3nupe1bf95/zudoxixoziwu.pdf
    • https://athensviptour.com/wp-content/plugins/super-forms/uploads/php/files/3c8a269bb25db8605bfd70643973ad78/35902104966.pdf
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/fcd8f96e5a93b7d80d5411f7810eb2a8/laromovuromojebanexate.pdf
    • http://www.ecostroyservis.ru/File/92523469367.pdf
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160755bbaa7580---kogewikaba.pdf
    • http://lnianemarzenie.pl/userfiles/file/fiwariderifarenoxuzafiwo.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/c2jpkj5bjsak8vjg35qf785n07/senilifi.pdf
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcb1e9de952---rovimozekoroseloku.pdf
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607d27868c6b3---17859264417.pdf
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160b8ecd44cab5---71837527975.pdf
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/1bf2bf41081ad68a8869fa9435248b05/68862413194.pdf
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607fcbafbf921---34021692231.pdf
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a451a34ea03---gigolavijagom.pdf
    • http://workcoop.org/fckeditor/userimages/file/20210612120333.pdf
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/mlem53kohk4jbgmd27g3r7f6u3/vigidujidigamuketip.pdf
    • http://reklama-v-sochi.com/ckfinder/userfiles/files/51110234264.pdf
    • 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_off0000e42c.bin
834a738e4c821bd0b909673177cdaaf7b46526ef3ce75b83e551b38589e01ddd
pdf-font-stream PDF embedded font (sfnt) at offset 0xE42C 10556 bytes
font_01_sfnt_off0000fc62.bin
214184b9c1851af80f8a6475e12be93ee5bda45f9bc0f5754f8cb60bb098c11f
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC62 16424 bytes
font_02_sfnt_off00012767.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12767 16792 bytes