Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b8babdb438f1dd2…

MALICIOUS

PDF

97.5 KB Created: 2021-08-11 14:11:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fec4cfdca62e60ea0a7d9b9a85ec1c2d SHA-1: f4a13dc376c7818945e41e02b1d930ed3fe52adb SHA-256: 5b8babdb438f1dd24bd626ca7bb93c23dd4fd0966c5d5cef531a0b06f6fd6cab
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://infrive.ru/uplcv?utm_term=realidades+2+capitulo+3b+examen+answers
    • https://travelworld.ro/userfiles/file/mofuwizogemogut.pdf
    • http://ristoranteibucanieri.it/userfiles/files/dilunagiko.pdf
    • https://sibservis.com/ckfinder/userfiles/files/nanagevavefadiduxekuruget.pdf
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/5aa3dd1697156c42d93209cb651fcc63/zisigudufoxepulejofuliju.pdf
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/lr0ioilcpsa482ogujvo6r8nk1/sujozuvunulofilivojo.pdf
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a8d856b867e---mibave.pdf
    • https://austarpharma.com/upload/files/rosirevowiliw.pdf
    • http://oicenglish.com/imagexx/files/merisup.pdf
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1ecd9e984d---81471836963.pdf
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/01frsr103ulh9i3js7quahkmc5/94209051044.pdf
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be7f3782240---84458469083.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4ce45c5d02---nemixaxovasiromefedafa.pdf
    • https://freedomhypnosisnyc.com/wp-content/plugins/super-forms/uploads/php/files/98791ac3d0ad82ea80961a58f833f4c5/75707243008.pdf
    • http://x04ydivan.ru/userfiles/file/18299514321.pdf
    • https://semagro-msw.ru/pics/images/file/16905448137.pdf
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/5a9f08ef8bba5760f1942d68decde22d/42739754467.pdf
    • http://signaturecruise.com/js/ckfinder/userfiles/files/loxedejajizidebisob.pdf
    • http://patp1ryb.ru/media/file/60913523507.pdf
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607758f6d5326---58303638795.pdf
    • http://kawoka.com/userfiles/file/51810447497.pdf
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c97cecc6c7b---gemivuj.pdf
    • http://eibich.de/layout/bilder/file/jupubunixovawuwoxu.pdf
    • http://whitesal.com/data/images/file/5521_20210719185105.pdf
    • http://jrpst.pl/userfiles/file/zewawurajuzunemizabedofot.pdf
    • http:///content/hmof/world_languages/hmhlanguage
    • 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_off00011274.bin
56146ad4d17d257cc89238a171af1c1539a3131807e42c9d177e3f974457e164
pdf-font-stream PDF embedded font (sfnt) at offset 0x11274 19036 bytes
font_01_sfnt_off00014377.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14377 16792 bytes
font_02_sfnt_off00015b8e.bin
86f69b82c94a983c1201355c27913b59c8b12cd6ccd485f8cb116426301cb6fa
pdf-font-stream PDF embedded font (sfnt) at offset 0x15B8E 11440 bytes