Malicious PDF — malware analysis report

Static analysis result for SHA-256 35ce39f6b1b65f47…

MALICIOUS

PDF

103.6 KB Created: 2021-07-10 10:08:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: e60e935cdc22e031ad1fe25d84d8dc69 SHA-1: 954af823a36dd379e5cfc5f7b957e3b32d25666f SHA-256: 35ce39f6b1b65f470b990d99a099b517d216789639a74337945d6f0ee587100c
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, containing numerous external URIs pointing to potentially compromised CMS upload directories and disposable hosting. The primary purpose appears to be redirecting users to malicious content or phishing sites, leveraging a technique often associated with spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9790

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://dprkoreatour.com/uploads/files/jetafaromijefilazotej.pdf In PDF document text
    • http://nelly-design.ru/upload/files/46681774772.pdfIn PDF document text
    • http://qca.ch/userfiles/file/89830640912.pdfIn PDF document text
    • http://gustosandvic.com/ckfinder/userfiles/files/gewopufobetewupofaliv.pdfIn PDF document text
    • https://nguyenthelong.net/userfiles/files/3472222264.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160a36eb136091---87433548041.pdfIn PDF document text
    • http://thunderstar.cn/userfiles/file/20210503091402531920243.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/14c81bda3f33f8dbc4e28c344382d561/17603060020.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4eea5e18df---98193939844.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/xemuruv.pdfIn PDF document text
    • http://24cvety.ru/upload/files/kagijaperinened.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ea43d1d283---62987734883.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608a8034bceb5---4297897982.pdfIn PDF document text
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/00uqin1qko1gqu06p2v647ndi3/68374395363.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/74fce3d6a3234269a42c31b1f32a4842/wimekubin.pdfIn PDF document text
    • https://euroroma-bg.org/files/file/39163594756.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/mguscj28cv02a5c7o338a75si5/ruvidazupolib.pdfIn PDF document text
    • http://youngshiny.com/userfiles/file/1622236559.pdfIn PDF document text
    • https://isosklo.cz./uploads/18562336135.pdfIn PDF document text
    • http://hanhthien.net/uploads/file/dozagonebufegeminuxobimu.pdfIn PDF document text
    • http://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/e6oi553jeuhp30h55kibrikie3/safodawuwebazemovirewu.pdfIn PDF document text
    • http://israel-aliya.com/wp-content/plugins/super-forms/uploads/php/files/748bb4c25bc71a3badea8d6ed51e7ee5/gukujifebozitubosolivuna.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/19411c94f2dd42b7e99b5b350f2b564d/jerurafufojetevarilamodin.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9b5e2705d---39668009267.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a99794c1fae---84734999991.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606fc246368da---nawajifaxolesalifatug.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=tenderfoot+4a+and+4bPDF 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_off00013596.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13596 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00014dad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14DAD 10220 bytes
SHA-256: a92f98f2b127fcdd32c4cfe4648d2a422a1914fa4410cfdb743e2945a4070401
font_02_sfnt_off000164c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x164C2 17092 bytes
SHA-256: 87a7da0fa65de17b07dff9e872f6e434abf9a68c247a53b869ae8391b61786f4