Malicious PDF — malware analysis report

Static analysis result for SHA-256 b80cc522dc2a4615…

MALICIOUS

PDF

85.8 KB Created: 2021-06-26 10:07:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 79b145b59c40f05db9f8422689c8c4e9 SHA-1: 116c5c185ae49d89ad1c52f434c05df96b75ec53 SHA-256: b80cc522dc2a4615cf0e9babb7b1f7be4fae364a3552a170a05fa09b1463158b
96 Risk Score

Malware Insights

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

The ML classifier strongly indicated maliciousness, and several heuristics identified the PDF as a link farm pointing to external PDFs hosted on compromised CMS uploads. The presence of numerous unknown URLs suggests a distribution mechanism for further malicious content or phishing attempts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • 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://lncxjzxxw.com/upload_fck/file/2021-5-18/20210518102855274018.pdf
    • https://twr1115.net/files/fckeditor/file/69106306085.pdf
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f4efcd03eb---telunorilebanubile.pdf
    • https://dtcprojects.com.au/wp-content/plugins/super-forms/uploads/php/files/tqgfluquah62pnqmnrtn0jd7qs/zelaku.pdf
    • http://backkwang.com/userData/board/file/67531469006.pdf
    • http://apcmagon.com/userfiles/tuposeroliloxedumaxavagir.pdf
    • https://alakharia.com/public_html/userfiles/file/61839273748.pdf
    • https://cor.org.ar/wp-content/plugins/super-forms/uploads/php/files/qho8415k5mcl67lqq1ft510kk4/poxibuligepon.pdf
    • https://classconnbio.com/img-jacson/files/wevotevusudebugiruzuvole.pdf
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6e1fcce098---voxuj.pdf
    • http://highlandlynxotic.com/clients/7/73/73cf6ae24f8ea70eb1cbac1dff6b0f9e/File/63034072261.pdf
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/830ab18162f339fc1111fc68cd202e32/vuzoridawemesukofelenobik.pdf
    • http://panziofabian.hu/fck_kepek/narepobase.pdf
    • http://seoulsquare.com/userfiles/file/dofopef.pdf
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606ff4b77c3bc---25018654295.pdf
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/471e93f309041a7de70ec6cdb1997672/67540787060.pdf
    • https://kogan-photo.ru/wp-content/plugins/super-forms/uploads/php/files/3a68c5dedb3623759fa28450ea55e771/63170569525.pdf
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c57c5886a5b---52437012097.pdf
    • https://advance-pack.com/editor_upload/file/35232304527.pdf
    • http://www.supercarrentalsofmiami.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a75aba42af---sagolofol.pdf
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/585996ed10d252bed900900106f0d409/talakoxowajipovaxefidek.pdf
    • http://gustosandvic.com/ckfinder/userfiles/files/63833667407.pdf
    • http://mispuntossaga.com/campannas/file/wisosogifidebevi.pdf
    • http://sumbulefendiegitimvakfi.com/resimler/files/wedejupisepevuvubag.pdf
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5cabda2e4c---58901299814.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=pruning+roses+in+summer
    • 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_off0000f02e.bin
715f1d915084e0d30651648d67285c719cf188dd7dfc04ea4bb432153163aa05
pdf-font-stream PDF embedded font (sfnt) at offset 0xF02E 10248 bytes
font_01_sfnt_off00010725.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10725 16792 bytes
font_02_sfnt_off00011f37.bin
83d63edcdfa5f1707ad632a958b236c3db8b7aca963933d023413e7dbdf93f46
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F37 16492 bytes