Malicious PDF — malware analysis report

Static analysis result for SHA-256 35540c586789e0b2…

MALICIOUS

PDF

83.8 KB Created: 2021-07-14 02:47:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 196dfec86eb50c571b8d254bd1dfa71c SHA-1: 401c452c9cf26ea1bd136d0afe89545f149db3ab SHA-256: 35540c586789e0b27c249a96e19bf44d7e081ec7197b2098ae315c0700f64e5c
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO poisoning to drive traffic to malicious sites. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9962

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://espacioschillout.es/images/admin/file/21272435711.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/ng8jneika12p8k4goko0vn6pun/20836991000.pdf
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/33520ea16ede14a773a832aabb441c86/95907298012.pdf
    • http://billedbutikken.dk/articlefiles/file/kojemigo.pdf
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160ad859b72c76---86922598879.pdf
    • https://aedwea.com/upload/foto/risurivajuk.pdf
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a1b2ef726d2---kewezekik.pdf
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080a63285e34---48869535840.pdf
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/0c44a599b7f312c508a5acd2e0c00921/tipivitejejesav.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/vs6pfgp6ah1mchi5dooh5b4hh3/zamaziwu.pdf
    • http://wawabed.pl/uploads/userfiles/file/8999332812.pdf
    • http://akgikorea.com/file_upload/fck_upfile/file/tizonedoxadufi.pdf
    • http://jfe.hk/userfiles/pavor.pdf
    • https://alamansyria.com/userfiles/file/8349146629.pdf
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/b42585401f300b8986b135ce941701ff/12435961583.pdf
    • https://blindnow.com/userfiles/file/worewabadugojowafoniru.pdf
    • http://greenlivinggarden.com/htdocs/UserFiles/file/86730530641.pdf
    • http://kimbuunguyen.com/uploads/userfiles/file/funurumivopixuv.pdf
    • http://e-sportis.com/images/upload/pususanomuvasip.pdf
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/9ffbf0e424907030f8b46c330f65bca9/78813889191.pdf
    • http://liccuza.ro/stiri_files/file/titig.pdf
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/fhibj9np67jfd0019i9fdim9j5/72894940767.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+take+a+nap+and+not+wake+up+tired
    • 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_off0000e693.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE693 16792 bytes
font_01_sfnt_off0000fea5.bin
a3f1d7c00cd8d6bee0337f4f08b546ced7ec92c7b0fd5510764519c0b10a1d76
pdf-font-stream PDF embedded font (sfnt) at offset 0xFEA5 16716 bytes
font_02_sfnt_off00012a34.bin
42e98defc221759566ce75eaf23227796605b10e91a55af2fe596d968b63ca16
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A34 10440 bytes