Malicious PDF — malware analysis report

Static analysis result for SHA-256 88e7583d3adc83c2…

MALICIOUS

PDF

85.9 KB Created: 2021-07-16 14:51:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 790f89546ce71f2a58176e95302fb5c0 SHA-1: ca31a7512e52d6200d8db3a6f2b2e04f38b8b605 SHA-256: 88e7583d3adc83c299660b1c42cb47b2660e2d180a405729e52bc434d7f2a246
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of multiple distinct hosts and the use of UTM parameters suggest an attempt to obscure the final destination and track campaign effectiveness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 6

  • 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 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://inwebjor.ru/uplcv?utm_term=dubliners+and+ulysses
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160818580b3054---faduw.pdf
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160d2f92542b4a---37910504238.pdf
    • http://farmaciacogliate.it/userfiles/files/87802026365.pdf
    • https://torgradio.ru/new/files/file/sapesimizapanuxedubokuper.pdf
    • http://coss-wynn-reunion.com/clients/d/db/dbe3622004495b304d8703879a486b7d/File/siniguxixibadevi.pdf
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/n6vaf7takq5qjg8mfdnr3de3h4/13722071124.pdf
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a53cda1505c---xamefame.pdf
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/93c7f0c0ecc94891931a9802f2ab06c6/pejumazureduwelobiwoko.pdf
    • http://jhdljz.com/userfiles/file/1626421911.pdf
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be572444a6d---88233573252.pdf
    • https://africanresearchcenter.com/userfiles/file/8890608482.pdf
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ca263b1de2---voremegop.pdf
    • https://stayinbranson.com/ckfinder/triplebuserfiles/file/73174445571.pdf
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/32f5515770c9dbe80f9fd7a3a966f824/97726772381.pdf
    • http://maility.pl_adresuserfiles/file/bobesozisoxofude.pdf
    • http://gorillatheory.com/admin/upload/file/53030329898.pdf
    • https://rmp-familienanzeigen.de/cms/files/16749661468.pdf
    • http://ristoranteyuri2.com/userfiles/file/67427990906.pdf
    • http://amoy-art.com/Upload/file/nifomazera.pdf
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/voj7nh550kn64sig9eqba2s0lk/dowewupije.pdf
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/160a4458cbfdd4---15276701238.pdf
    • https://laser-arena.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160785cc081ecf---gobumupifebufodaru.pdf
    • http://e1pl2.nazwa.pl/busy/fotki/file/zatugepom.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_off0000edd7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD7 16792 bytes
font_01_sfnt_off000105e9.bin
3095d51c6f1b70d6fee2029a0e1fb40616db1c6b32c79843a9c1b1924bd5e4a6
pdf-font-stream PDF embedded font (sfnt) at offset 0x105E9 18184 bytes
font_02_sfnt_off000132e6.bin
364089ba0d2985d095f49c7421321fda000fb1faf4b33c6736bded92fda673a7
pdf-font-stream PDF embedded font (sfnt) at offset 0x132E6 10380 bytes