Malicious PDF — malware analysis report

Static analysis result for SHA-256 a24a76050d38b7d1…

MALICIOUS

PDF

112.4 KB Created: 2021-07-04 07:43:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b64a3bf949d046cd0b2494fe245354d0 SHA-1: f55981b77bf88673862266e607a8483c73ab6759 SHA-256: a24a76050d38b7d14b5ad630e839543a9a31eb9be2076d2c4fe4cec1711d078e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier as malicious. It contains numerous external URLs, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a strong intent to lead users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://crewmak.ru/uplcv?utm_term=halo+effect+experiment+1977
    • http://nakamurasangyou.jp/app/webroot/uploads/files/18295215310.pdf
    • http://ingatlantv.tv/userfiles/files/laxexor.pdf
    • https://wodepcb.cn/uploadfiles/files/81292488361.pdf
    • http://writtenmail.com/upload_images/file/wumavedizuwiwevefebak.pdf
    • https://www.foundationofhope.org/wp-content/plugins/formcraft/file-upload/server/content/files/160801b83a8782---53330694615.pdf
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/6efad8c75fa4442be9b1ec02a3f9225a/7471555130.pdf
    • https://marljivo.hr/userfiles/file/misor.pdf
    • https://fullgame.hu/uploads/files/72697751574.pdf
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606d4eba87e76---89733984431.pdf
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/bapusagamafavefuritemu.pdf
    • http://grandp.ru/userfiles/file/pofitalupokurotosokor.pdf
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5be1f36595---dixifeburato.pdf
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/gdvvqku8qpaos1okmfncgp9642/tiriwukeferalopojogedogen.pdf
    • https://arerp.kr/data/file///27297799975.pdf
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab3db8203b4---13615579806.pdf
    • https://immobiliaresancarlotrieste.it/file/taxezepupinuwefimamuw.pdf
    • http://belgium-ex.com/images/blog//file/88172484703.pdf
    • http://rusiuojigalvoji.lt/wp-content/plugins/formcraft/file-upload/server/content/files/160a72a0aee88a---nomowipolugevanofa.pdf
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6407229555---71921680859.pdf
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d2aba26aae---zelojolenusune.pdf
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160911d2cd2532---36326543833.pdf
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/u3isiac85ur3d55m1893q23gs2/waloruno.pdf
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071dd2383808---vobivoxezugevu.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_off00015336.bin
6cfc1664b4493348577bdde25426a83b3ee4a2d4af749a98f71befbd9f580cac
pdf-font-stream PDF embedded font (sfnt) at offset 0x15336 18816 bytes
font_01_sfnt_off00018377.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x18377 16792 bytes
font_02_sfnt_off00019b8e.bin
28599f046e092df44a1d84d5f7a683276a3c642dc6560a10ac6fbd03edee7a6d
pdf-font-stream PDF embedded font (sfnt) at offset 0x19B8E 10836 bytes