Malicious PDF — malware analysis report

Static analysis result for SHA-256 31597dbc13c46351…

MALICIOUS

PDF

87.4 KB Created: 2021-06-25 22:50:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 49124722658f4fd54afecf911b358f16 SHA-1: 01d24c63765f7d233c1181fa8d84f9df0c5ee5f2 SHA-256: 31597dbc13c46351bc6c7da0219cde1c3889fd6fbd02490a562d84bc2105a546
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to potentially compromised WordPress upload storage, suggesting it's used to host or redirect to malicious content. The presence of multiple unknown URLs reinforces the phishing or malware distribution intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://lerong.vn/wp-content/plugins/super-forms/uploads/php/files/c4b400a1817302cf77b21f93cc3c7360/18961230292.pdf
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/370b7068dead1dc08716fe3b1f2f2798/xeverojuniwitirex.pdf
    • http://daiichihr.com/uploads/news_file/fibusesaki.pdf
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080bd3c300ff---zurusex.pdf
    • http://toyteepee.com/uploadfiles/file/210625111804021675rxkxnt.pdf
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7d24e32290---gamizogipomolunixutuge.pdf
    • http://atthaya.com/file_media/file_image/file/52249349090.pdf
    • http://ligonfamilyreunion.org/clients/9/9a/9a44987365eba454cd9b2deda39aa7c0/File/faloxobiniboz.pdf
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/pqoe94q1r8jlml7e4rpr6ncvut/79204374751.pdf
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/d15ac64c49729b90703255edf5677dc8/86276178722.pdf
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/lfv6hbvtjqccll03u5nttg4m34/57444996772.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607625930822e---45019128903.pdf
    • http://soles2walk.cz/data/file/17411251317.pdf
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079aa8c163af---danivedesawifarigines.pdf
    • https://amd-export.com/site/upload/file/85973674149.pdf
    • http://beiks.info/public/file/8940426376.pdf
    • https://advance-pack.com/editor_upload/file/43935573287.pdf
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/9f6f61f27676e7068e8a7010ba0dea0d/wugopixexobewidisefe.pdf
    • http://instant-image.net/UserFiles/Site/File/49801977247.pdf
    • https://www.ppmcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/f8ocppcr0bbiht44rp3em97cpk/41118470759.pdf
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607df9ebc3efd---71284239840.pdf
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/0c6d006e708bb3fb0d7c9b3261a83b74/jipabuxaxug.pdf
    • http://velkoobchod-man.eu/ckfinder/userfiles/files/39988590108.pdf
    • http://tamker.hu/userfiles/file/98616384978.pdf
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/aqsraqlc53misprdp6dtcvh8o3/matupi.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=difference+between+deductive+method+and+inductive+method
    • 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_off0000f275.bin
cfa6e19490e3ac180215e85ceb9dae1d39837cc6211306b86501b3b96efebfd7
pdf-font-stream PDF embedded font (sfnt) at offset 0xF275 17008 bytes
font_01_sfnt_off00011e6b.bin
e60973ce38b95ffd44d0e6dad709dc225ed2109e746f042c7dd5012cbf8738a7
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E6B 10920 bytes
font_02_sfnt_off00013799.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13799 16792 bytes