Malicious PDF — malware analysis report

Static analysis result for SHA-256 487681b8b049a81e…

MALICIOUS

PDF

84.9 KB Created: 2021-07-07 17:44:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0e7aa4e22b449ef7d06bfb3127f52eff SHA-1: 22bf46795c6ad10b754d985012993571b142beb0 SHA-256: 487681b8b049a81e0830d1756bd37cfa1948452d01104a0848275b17aa83c836
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to PDF files hosted on various websites, some of which appear to be compromised CMS uploads. The primary purpose seems to be redirecting users to potentially malicious content, aligning with phishing or malware distribution tactics.

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 http://dabaizhongxue.com/upload_fck/file/2021-5-20/20210520090830333019.pdf
    • http://cnpair.com/userfiles/file/25031923505.pdf
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/ef7208af89beb1c86a7ed000c12325ef/93337448478.pdf
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0f40239f48---dalifetubalexata.pdf
    • http://tnslib.net/userfiles/files/58196453574.pdf
    • https://pass-eco-energies.com/ckfinder/userfiles/files/66477226432.pdf
    • https://tahitotfaluovodak.hu/ckfinder/userfiles/files/fesawavotigewipuj.pdf
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/ro6bvv2mqb0gapi0922fsec30k/bijifew.pdf
    • https://capital-tic.com/upload/ckfinder_temp/files/20210601112551.pdf
    • https://propactionvehiclesuk.tv/userfiles/files/38698000204.pdf
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/6f5c23d9f41e104669a861157bf1dbdd/55514421660.pdf
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/cc3350afa7fbfa29753dd6cedb2f62d4/kavajidawekunomoxani.pdf
    • https://shopinhome.com/ci/userfiles/files/kibosajori.pdf
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/mrp3primk11uplofbkf8og7fn4/51563809568.pdf
    • http://pobierzplik.pl/uploads/files/zenufanorakuvege.pdf
    • https://limmaginebistrot.com/file/kazoni.pdf
    • http://stlukesmn.org/clients/17773/File/jidebonamagonojoxejit.pdf
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/iic6bv2h5pre96fsdgu52l9mac/nuxarigon.pdf
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/fb3e269315358bb847853f63f2fa8a94/disolesojogewebo.pdf
    • https://sgdivorcelawyers.com/wp-content/plugins/super-forms/uploads/php/files/92639b956b0eb615f61037d7dae5d25d/jovanatota.pdf
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/2u2ob7jkodokaufs4mndo1pql3/jatelelewuboxire.pdf
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/71b45a66f040ca2d83970efdf7d0e493/77703698912.pdf
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/2d9da218defeda1191b249ed7875b839/83802137887.pdf
    • http://ohappy.org/userData/board/file/gebemarenasokizafuvenajet.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=texture+of+a+song
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/198a0cb2de5ca73e07cad317d7d7a0a5/tikukuw.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_off0000ead1.bin
14b8f257eeff44330eea9c0707925fedafeea29a95d0161fb67daf65dded3231
pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD1 16940 bytes
font_01_sfnt_off0001168c.bin
5ba828060cd87bd49d6c2a42bc8286445a3793a3123e42d9d4cb32d2c2ef201b
pdf-font-stream PDF embedded font (sfnt) at offset 0x1168C 10416 bytes
font_02_sfnt_off00012e5c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E5C 16792 bytes