Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f4e36d7c12b2877…

MALICIOUS

PDF

88.3 KB Created: 2021-07-01 18:41:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 35e1056673f6cdbe21d06ab31d457170 SHA-1: 173bfa23ff31cbeda3116e704578214a3cd3e834 SHA-256: 8f4e36d7c12b2877d30a0ad1b7c46bf1cb85dd7f89a3fcbde635a02cca50c598
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised WordPress sites or are hosted on disposable domains, indicating a link farm or SEO manipulation tactic. ClamAV and ML classifiers also flagged this PDF as malicious, specifically as a phishing trojan. The document body is unreadable, but the heuristic firings strongly suggest a malicious intent related to link distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://bedandbreakfastchia.it/userfiles/file/fusatosukevipu.pdf
    • http://airsoft1.ro/files/file/31355374207.pdf
    • http://atut-biuro.com/uploaded/file/duziwunulitosa.pdf
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084159c0c58d---zelir.pdf
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/d25bfdb56cba90f72a3fae69bbf3abcb/85703992776.pdf
    • http://apcmagon.com/userfiles/26673462088.pdf
    • http://christschoolblr.in/userfiles/file/julededagajozovumepu.pdf
    • http://brunsfamilyreunion.org/clients/e/e7/e70b0594429ddd28dfd4dd2f61c76e80/File/gasafegubumurutiriruni.pdf
    • http://boilerservis.ru/uploads/files/19594370475.pdf
    • http://aryajob.com/user_upload/file/12566378160.pdf
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609c35eebe8ed---vedabimafa.pdf
    • https://widepolymers.com/userfiles/file/10935406226.pdf
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/aa93831d6224f2af0740536456cd14cb/45254373568.pdf
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608038cc86e2b---48673745456.pdf
    • http://turexpert.md/userfiles/images/file/3181085693.pdf
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bbfc3210bb1---84942051697.pdf
    • https://www.movingwithmagna.com/wp-content/plugins/super-forms/uploads/php/files/7eb8296c05cfb2099922fc8d5d1004e4/bovimibij.pdf
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16099c594a46aa---dedosezugitu.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609472df3d54e---zejazomakineruku.pdf
    • http://toeicspeaking.net/_UploadFile/Images/file/vinoroxerepenavituzutuwab.pdf
    • http://biotop-zamosc.pl/userfiles/file/55090320450.pdf
    • https://a2designbg.com/userfiles/file/94830997533.pdf
    • https://haysalon.com/public_html/userfiles/file/gumamutulawodaxagawijo.pdf
    • http://www.hussco-steel.com/husscofiles/files/zufusifikofufebizijapude.pdf
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160947472c99df---47701570389.pdf
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bacb2c3c16b---28652953462.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=rickets+causes+symptoms+and+treatment
    • 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_off0000f384.bin
bb5a83a5973892a0d08322f31f6fc1097de3d3fb006266ce618038f3b287fb32
pdf-font-stream PDF embedded font (sfnt) at offset 0xF384 10980 bytes
font_01_sfnt_off00010d0d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D0D 16792 bytes
font_02_sfnt_off0001251f.bin
dde95ede57cc21ccab0cfe274f86cd351c028ca4840f70536243c6ab76a4e3b1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1251F 17112 bytes