Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a4ea36588d66fdc…

MALICIOUS

PDF

78.8 KB Created: 2021-06-30 23:43:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a14ea2e4e8c9f83348f8c4470753bccc SHA-1: 39504cd34cad67347e57ceaedca25ba0bff1a561 SHA-256: 4a4ea36588d66fdc49a98a27763bc45bae1f933ee7baaa572ca490bed8403eb0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF contains a link farm pointing to multiple compromised WordPress sites, which in turn host other PDF files. This structure is indicative of a phishing or malware distribution campaign, where users are lured to click on links that ultimately lead to malicious content. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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 http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/160808ca133b26---nudap.pdf
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/6112d9b99ac207959dcd76d4831a4622/35733530058.pdf
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a406e2223df---89792868087.pdf
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160716700dce89---kilojuwisu.pdf
    • http://skncn.com/u/files/32357239672.pdf
    • http://tuderprogettazione.it/userfiles/files/8663636910.pdf
    • http://wib24-admin.de/uploads/file/9159162102.pdf
    • https://twfern.org/upload/ckfinder_temp/files/20210620070837.pdf
    • https://www.picmephotoboothhire.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608a4136cc15b---46772054293.pdf
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073b3f515d1b---96261239750.pdf
    • https://turismoporsantander.com/aym_image/files/93846044909.pdf
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/160731628093f0---61413272520.pdf
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b9139a0243---ganenosuvirejefeb.pdf
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa8504e6b15---nupedibosilotoxez.pdf
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/bmptda60l3hmb7h8318s6bk9v5/zozif.pdf
    • http://kulturazebrak.cz/userfiles/soxutubamorukadeb.pdf
    • http://cedule-plachty.cz/files/file/75314244646.pdf
    • http://ncabhsa.com/clients/875427/File/10405376742.pdf
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/vfd2fb8h3haoh12qq8tsq9ln74/xuzuxupinu.pdf
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/b8fb0130ab521903eb60921909206571/21366377880.pdf
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160856be7904f8---73479238980.pdf
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1606f21cfcb0e4---zuturufepepulinodenebik.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=how+to+attach+pdf+to+pdf+document
    • 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_off0000d047.bin
f12285f1f03e3be70e1a3bbe0766c4ed5263ff610b1c164a2c2fbc38ed9ed4e2
pdf-font-stream PDF embedded font (sfnt) at offset 0xD047 10656 bytes
font_01_sfnt_off0000e88f.bin
ffb17585a6b9cd5262cded6d2843425c53e8161677814f7777c0ac9e21cc8396
pdf-font-stream PDF embedded font (sfnt) at offset 0xE88F 16896 bytes
font_02_sfnt_off0001147b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1147B 16792 bytes