Malicious PDF — malware analysis report

Static analysis result for SHA-256 1ee0120df8925ed2…

MALICIOUS

PDF

88.3 KB Created: 2021-06-29 14:21:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 12ad7968828a6872c6e4827e39fdf76c SHA-1: 1f8b6ba35322ea7cb55eec4fb395316b3549a9d6 SHA-256: 1ee0120df8925ed2143eab1e67d1b20eb37b0b7bb4f93872ae86f75dc54be317
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document that contains numerous links to external resources, many of which point to compromised WordPress sites. The heuristic PDF_RANDOM_URL_LINK and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM indicate that these links are likely intended to host and distribute malicious payloads. The ML classifier and ClamAV detection further support the malicious nature of this file, suggesting it's a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • 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 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://nowackleverkusen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b43330718f9---gumuta.pdf
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/160c401569b510---fozuvazazigewegoxapawin.pdf
    • https://rclurie.com/wp-content/plugins/super-forms/uploads/php/files/90aba127b7f64192d1eff5d4fe73628c/2387916123.pdf
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/160733250ef0e1---98815610857.pdf
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f13401c4ee---7619556034.pdf
    • http://rusiuojigalvoji.lt/wp-content/plugins/formcraft/file-upload/server/content/files/160870f8926ee0---35441430441.pdf
    • http://twfbs.com/ckfinder/userfiles/files/pumowodozokakizode.pdf
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/9adutsi6vaa00ki10sk9oqcrb6/62262502005.pdf
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/1608c2d0d82541---tanazitawitezinavazavud.pdf
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b54b8880054---juxuvin.pdf
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/ca52c427240d42f6fd011a7700c3a983/98703750966.pdf
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f562667f1a---tifevu.pdf
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/1b0d6e6d5dd9d83a451f2be03965d053/23314677007.pdf
    • https://sunwayhk.com/louis/STARKGROUP/ckfinder/userfiles/files/90813777669.pdf
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/16073c28458ebb---tamixikikamizurobax.pdf
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/c7f02350893d7ab28b746dcb0606d460/ninapakukeperezegujaxe.pdf
    • http://essiac.cz/UserFiles/file/zokolotevifevifepodifulas.pdf
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/f8edf9de26ac3fbd5f5a259a26fab0ac/ruxewupixereteto.pdf
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cda46a2b37b---54770504646.pdf
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/572aa54e0c150135c42c24910ada788b/paropiweke.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=connective+tissue+histology+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_off0000f6b2.bin
cad836fd5a93f9dacf8e02add91651bacdf52f6a1d5f3ea2584af556f7ddeb8c
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6B2 10948 bytes
font_01_sfnt_off00010fdf.bin
465495a6327654dea6f0942d623cf7f496d89a0053f2fa8d8a15d2cc0da4ed95
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FDF 16852 bytes
font_02_sfnt_off00013bdf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13BDF 16792 bytes