Malicious PDF — malware analysis report

Static analysis result for SHA-256 899b42aabdbeadf0…

MALICIOUS

PDF

81.8 KB Created: 2021-09-01 21:06:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5d1ec30d79b68604ba14b11075573fbf SHA-1: 065dac896b362c90477c1d22ac36e48fdbbdf645 SHA-256: 899b42aabdbeadf043e3fadf882e301cb3a46670fb795f861bff4f12fe75e6a3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML and ClamAV as malicious, indicating a phishing or trojan payload. It contains numerous links to external websites, many hosted on compromised CMS platforms, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this. No scripts were extracted, but the document's structure and embedded links point towards a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607a70aeacb21---buxixijifasujumiwokexer.pdf
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/lumlng5k0gpmub8do3akhshpj0/53604655560.pdf
    • http://sdds.be/userfiles/file/58667077083.pdf
    • http://scheiden-maassluis.nl/uploads//file/sosonotegirukajinizex.pdf
    • http://93564497.com/userfiles/18419867738.pdf
    • http://uralinteh.com/uploads/files/21363598519.pdf
    • https://plswa.com/wp-content/plugins/super-forms/uploads/php/files/43d81ba46c6f477126a8896d9c4eeecc/6957251432.pdf
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607a45ec073c8---fegulokubexonov.pdf
    • http://alituncer.com/userfiles/file/62880959577.pdf
    • https://indirimlipin.com/calisma2/files/uploads/67605989891.pdf
    • http://bioterapiazabiegi.pl/obrazy/file/putibumag.pdf
    • http://alphaconsultinggroup.us/vpw/images/file/37502587961.pdf
    • http://cadeco.com/testingsites/advantage_aviation/assets/media/file/kefefexawiwuz.pdf
    • http://selfmadefilms.nl/userfiles/files/25899129707.pdf
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095f872cd258---28802779739.pdf
    • http://stihoplet.by/upload/editor/files/71792504517.pdf
    • https://beaszemin.com/files/birotamozuw.pdf
    • http://ahcxdq.com/uploads/file/290637013845.pdf
    • http://skipjackpoke.com/ckfinder/userfiles/files/98083435192.pdf
    • http://bayernglobal.de/userVZ//file/72622598154.pdf
    • http://zap-interactive.com/uploads/files/zojalatataxoburomove.pdf
    • http://cancercareresearch.com/userfiles/file/balavimisabibo.pdf
    • https://horizontire.com/userfiles/file/nenok.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=lateral+in+medical+terms
    • 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_off0000ddd3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDD3 16792 bytes
font_01_sfnt_off0000f5e5.bin
8c5c5667841c4c8b45d99138631ab1e5cbcb8cb982fa51d62216da64d3f18292
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5E5 17636 bytes
font_02_sfnt_off000122e9.bin
85952dcf56137340a4c51381688f176a6325e20078adc350b6002a8bea9b8526
pdf-font-stream PDF embedded font (sfnt) at offset 0x122E9 10368 bytes