Malicious PDF — malware analysis report

Static analysis result for SHA-256 16d78b89f411f1ea…

MALICIOUS

PDF

85.8 KB Created: 2021-06-27 06:53:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6b95439c8ffe5327a2d6da849d618380 SHA-1: 1abc95cf88fbbb5e3d78a073401a7273222ad37d SHA-256: 16d78b89f411f1eafdc19d0fa10841e050e1cbe5a3e3ec8ce5fc2a1dac53a6e2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by multiple heuristics as containing a link farm hosted on compromised WordPress sites, with numerous distinct hosts identified. The ML classifier and ClamAV also strongly indicated maliciousness. While no scripts were explicitly extracted, the presence of numerous URLs pointing to potentially compromised CMS uploads suggests an attempt to host malicious content or redirect users, aligning with a phishing or malware distribution attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/ufkiehadef8872jkmvr52qakde/jorixeburezirofo.pdf
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606e2a39e8763---40445526595.pdf
    • http://novussiteyonetimi.com/uploads/file/fozosunaxijovelufokebakij.pdf
    • http://velo.hu/UserFiles//file/joxebegumon.pdf
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b9c9b61e026---499750429.pdf
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cc823b3523---ligozovo.pdf
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089cdbd0868a---dugonuromukapabozofo.pdf
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7c6b14c1184781a4f1323ed915350c3e/mubekuvobebejag.pdf
    • https://www.proctoloji.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ddf4882caa---11283438799.pdf
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/2rloama5iuf0kq539q1fkh1adb/xuxir.pdf
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/r3cehop0iq5avqv1v5g9vtg5pv/60455582300.pdf
    • http://xn--h49al33a2zdp0eo1x.com/DATA/file/20210606035237.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074c31095c3d---6109836804.pdf
    • https://imagebeaute.fr/userfiles/file/vefavavi.pdf
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609d556d71270---97770126307.pdf
    • http://rgn2u.com/userfiles/files/50346198747.pdf
    • https://terlickodds.cz/www/www/fckphotos/file/46844910869.pdf
    • http://www.justgiveahand.org/wp-content/plugins/formcraft/file-upload/server/content/files/160805edb7b37c---fajekerinanekin.pdf
    • http://saovietgroup.com/upload/FCK/file/88326820809.pdf
    • http://imaginove.eu/data/Files/gijapukimegewugudoj.pdf
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8a7d28dc5---45258271415.pdf
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/6d80c32e4e0ad3b26875bc304af51552/49076806550.pdf
    • http://arniestribu.com/campannas/file/16447233206.pdf
    • https://directorvincentchow.com/fck_filemanager_upload/file/vopisuvumibitivumojamamud.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+multiply+a+decimal+number+with+a+whole+number
    • 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_off0000e71f.bin
7b8dee37e98e19e4b7fdac3d166c904851bef7bf318fbcb55458cb8d1b56f32e
pdf-font-stream PDF embedded font (sfnt) at offset 0xE71F 11044 bytes
font_01_sfnt_off0001005c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1005C 16792 bytes
font_02_sfnt_off0001186e.bin
d751508eb5ddc37787495537de77d6054264c6907b0b01bc972f4be2f47baaad
pdf-font-stream PDF embedded font (sfnt) at offset 0x1186E 19076 bytes