Malicious PDF — malware analysis report

Static analysis result for SHA-256 79a1a5202c227e4d…

MALICIOUS

PDF

83.4 KB Created: 2021-07-29 12:45:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 231421900cc433082ef1dbc56684f6d8 SHA-1: c20fc947b1bde1cc0b4f5f476995ca2b9ac5bfe3 SHA-256: 79a1a5202c227e4dc576c397faabd52480f27a067fbd7235a1447f0693fda3ce
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file exhibits characteristics of a malicious link farm, as indicated by multiple heuristics flagging it as a PDF with random and compromised CMS upload links. The numerous embedded URLs point to various domains, many of which are associated with compromised WordPress installations or disposable hosting, suggesting an attempt to distribute malicious content or phish users. The ML classifier and ClamAV detection further support its malicious nature, likely serving as a lure to download further payloads or redirect to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://smidgel.ru/uplcv?utm_term=what+is+the+polarity+of+the+molecule+sf4
    • http://okuninka-biale.pl/userfiles/file/48031819385.pdf
    • http://reutlinger.pl/userfiles/file/90674958815.pdf
    • https://minipowerpack.net/upload/files/30817465760.pdf
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160d280e65f226---77134873219.pdf
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160961d74b079a---mexegivat.pdf
    • http://worldtile.net/jangheung/userfiles/file/56781305650.pdf
    • http://xn--80aatg4aaaddkhfhbf3evf.xn--p1ai/ckfinder/userfiles/files/34196109294.pdf
    • https://5a.ro/ckfinder/userfiles/files/vugilaraxobede.pdf
    • http://dexgerm.com/data/file/userfiles/files/moponuw.pdf
    • http://messtores.ca/fck_user_files/file/zuxolufijojifuvedejikari.pdf
    • https://zegabilisim.com/calisma2/files/uploads/90621533535.pdf
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608e8f289084f---84452177242.pdf
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c900ccb134a---11421580643.pdf
    • http://apsencollege.org/test/fckeditor/file/giwitalanapafa.pdf
    • https://systematix.pl/userfiles/file/64806042741.pdf
    • http://clinicaveterinariacittadivignola.com/userfiles/files/97056539147.pdf
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/7b9e8rcnegsoald6saqur5051b/9666906690.pdf
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/18b1a9c347680393d73f42e00f8b06a9/97798246109.pdf
    • https://tedvandergulik.nl/userimages/file/2176313268.pdf
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/2f33eb7f16ac42bbaf24043e3790d51b/62533783163.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_off0000de01.bin
85d42d71dccb2d03e26cee60a38144c4ae0dc91f95a87a004435c0edaf5eba4a
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE01 18464 bytes
font_01_sfnt_off00010d31.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D31 16792 bytes
font_02_sfnt_off00012548.bin
e49226521cadada9943c6a66e650bd482174b3fe6071da200577de0e6db0af85
pdf-font-stream PDF embedded font (sfnt) at offset 0x12548 10924 bytes