Malicious PDF — malware analysis report

Static analysis result for SHA-256 839859c4fa5894c8…

MALICIOUS

PDF

88.3 KB Created: 2021-07-20 01:41:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 833962afb28ccd6161eb093bce6a20e4 SHA-1: df2aad9a1f1a7a0a1ff470b02fba703fa417572b SHA-256: 839859c4fa5894c8237cdbd018caeda69d07b7466f90cc96ce5fa051e27670fb
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF document exhibits characteristics of a callback phishing or tech-support scam, as indicated by the 'SE_CALLBACK_LURE' heuristic. The presence of numerous external links, many pointing to compromised CMS upload directories or disposable hosting, suggests an attempt to distribute malicious content or redirect users to phishing sites. While no scripts were explicitly extracted, the ML classifier and ClamAV detection strongly indicate malicious intent, likely involving exploitation of PDF vulnerabilities to execute a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://acrgroup.nl/userfiles/file/pedixadugabujunapa.pdf
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/lo49v8tdt8l8f6vmah7ggobut2/tuwufewoboviw.pdf
    • http://kasystemofkarate.com/clients/861259/File/gutukipol.pdf
    • http://dollreunion2020.com/clients/4/43/4392dc7a9e9236654a628da0af121bbb/File/nemabiluwujuvirupogidof.pdf
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/2dde6702a04410cd6be0998c365c158c/47858736314.pdf
    • https://edu-mate.kr/_UploadFile/Images/file/60531516688.pdf
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/8ed0eaaa3ae7e9ae5da0255d1006d385/fobuxoreludinefugipekirir.pdf
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ca6189ca49---16841694394.pdf
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b311d539532---gamiziw.pdf
    • http://chrislahoda.ca/userfiles/file/38540708747.pdf
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b3b3a747e01---67213861362.pdf
    • http://hi-reid-solutions.com/wp-content/plugins/super-forms/uploads/php/files/ac8d60e713877e5f82eeca662dfec429/jisidofijozuzogixuzakotoj.pdf
    • http://clinicaveterinariaalbese.eu/userfiles/files/pomeramufegajek.pdf
    • http://andrelandberg.com/userfiles/file/furolexu.pdf
    • https://tlpnw.com/wp-content/plugins/super-forms/uploads/php/files/3008461ea16d5bd065b515c206bea7d4/nojixutirigupuk.pdf
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8ee189c618---25651604052.pdf
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/5187528083ed031e64fa1a811da6b750/jixarema.pdf
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606fecf6b2841---fataxinazojut.pdf
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160924f4eae664---xuxozem.pdf
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/mgnhec3fvtfcc4tatcljqt4bvf/88088719980.pdf
    • https://parklanehotel.asia/userfiles/file/99948658108.pdf
    • http://revucue.com/ckfinder/userfiles/files/danazevoxagasotogejide.pdf
    • http://guides2alpes.fr/uploads/file/21966904501.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=exercises+with+present+perfect+and+present+perfect+continuous
    • 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_off0000f520.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF520 16792 bytes
font_01_sfnt_off00010d37.bin
4478037621e37891e21c7fc3c0f68ebe27f23c81d407f30d8ba1cbe61a17a028
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D37 10940 bytes
font_02_sfnt_off0001269b.bin
38a2931eb71def78ed0b54256baba274d3f9349765d7cc96fdaa50b768988854
pdf-font-stream PDF embedded font (sfnt) at offset 0x1269B 17452 bytes