Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1d5d0e79601f18d…

MALICIOUS

PDF

68.8 KB Created: 2021-09-25 23:00:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 275fea003b172929d31d3cec7a971442 SHA-1: 5ed7f04354a9ec97ee07c3f4dfcedd222ec3094f SHA-256: c1d5d0e79601f18d2546663179684febb9e34c8151a621866044a7703e0639e2
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous embedded URLs that form a link farm, many pointing to compromised WordPress sites or disposable hosting, suggesting an attempt to distribute phishing content or redirect to malware. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further indicating a non-legitimate purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://cructi.ru/uplcv?utm_term=new+tom+and+jerry+movie+coming+out
    • https://masterjobintl.com/ckfinder/userfiles/files/dibebani.pdf
    • http://kesherisrael.com/uploadEditor/files/segeribuxozowiluvusavup.pdf
    • http://autovoda.ru/upload/files/duwuxujitebi.pdf
    • http://hattingtoemrerogsnedker.dk/userfiles/file/xebimelu.pdf
    • http://xn----7sbjvweekof5d.xn--p1ai/files/files/jojatuxoxezubo.pdf
    • http://chupanhnoithat.vn/upload/files/8553167478.pdf
    • http://mama-care.com/UserFiles/file/morelevafoxizosetava.pdf
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/39cbf8307724b6d958e7b40f3ee6661c/73038905989.pdf
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/pmvtc1ci9sj851cfilt9dlt296/17946255500.pdf
    • http://taikenplan.jp/ckfinder/userfiles/files/44631354661.pdf
    • http://janaturismointegrato.com/uploads/file/linom.pdf
    • https://freebcard.com/ckfinder/userfiles/files/zitizomazuju.pdf
    • http://sjzhtchem.com/upload/files/welegow.pdf
    • http://lapempi.nl/ckfinder/userfiles/files/50239383626.pdf
    • http://willettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/21768959067.pdf
    • https://baobiachau.com/luutru/files/60909797969.pdf
    • http://www.prodomasa.com/ckfinder/userfiles/files/53547883909.pdf
    • http://vantaidongsaigon.com/uploads/files/78429922018.pdf
    • https://westhigienia.hu/editor_up/2057208318.pdf
    • http://putzlappenborner.at/editor_up/simopobibedizu.pdf
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/16143c5b937d62---gikarofobigulalowibataw.pdf
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614586a66fd22---32030117289.pdf
    • http://szamosiszerviz.hu/feltoltott/files/wojit.pdf
    • http://jobsandhi.com/uploaded_files/userfiles/files/43722227763.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_off0000b009.bin
36aa91fb3b7e4ee417a336b319d618f23d71ea044d30eaa17e26f4119cfe69c5
pdf-font-stream PDF embedded font (sfnt) at offset 0xB009 14532 bytes
font_01_sfnt_off0000d475.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD475 16792 bytes
font_02_sfnt_off0000ec8c.bin
d0017f01da7045e7cc6ee3f9ed551bbf7766f01026b1bc2c4191b676d19c767c
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC8C 10972 bytes