Malicious PDF — malware analysis report

Static analysis result for SHA-256 a838857305c5ce7d…

MALICIOUS

PDF

88.9 KB Created: 2021-07-31 23:28:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 8e871c83d98f7bf3c74c8d697acf106f SHA-1: c33b560aebc6b17a35521935f75186a84efda8ad SHA-256: a838857305c5ce7d09a91ca88795a7804f09dc19efd8479a71e9d44d30b34024
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs that form a link farm, many pointing to compromised WordPress sites. These links likely serve to obscure the true destination and distribute malicious content, as indicated by the ClamAV detection and ML classifier. The presence of multiple distinct hosts and the use of UTM parameters suggest an attempt to evade detection and potentially perform SEO poisoning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://archism.ru/uplcv?utm_term=davis%27s+canadian+drug+guide+for+nurses+17th+edition PDF link annotation
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/ekog80bshicm9t0q5sj5gciq21/87196978509.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/1606d50653a6ca---voburijedubu.pdfIn PDF document text
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/a60ad3f57927ae408f5d256a89a9eee1/raxemuladajosofugavo.pdfIn PDF document text
    • http://tafgambiatours.com/userfiles/file/godojimojezitosudil.pdfIn PDF document text
    • https://scavilecis.it/userfiles/file/jowonimod.pdfIn PDF document text
    • http://gapoom.com/upload/fckeditor/file/sidudotogekexiri.pdfIn PDF document text
    • http://ambulatorioveterinariorigolon.eu/userfiles/files/36664784912.pdfIn PDF document text
    • http://kmkonsult.cz/userfiles/file/bunisimafifokuf.pdfIn PDF document text
    • http://goshaggers.com/clients/2/2c/2ce39afd4341152949bc146f79210d6f/File/linilije.pdfIn PDF document text
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/7438731f591d18c2b1dc2a8576537ecc/38908010750.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/tofinopo.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/16085d60faae59---juvumugupaxo.pdfIn PDF document text
    • https://wavemed.it/wp-content/plugins/super-forms/uploads/php/files/59c3ced9181d8c79341bc2ca532b1f1a/13196097642.pdfIn PDF document text
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/7d717217ca94ce354aff4659251bde68/linuliwet.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/1610104cfa936d---mukoxetixen.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/8m70dlur3erlap8apj3a9vpi15/pisazuvi.pdfIn PDF document text
    • http://art-lan.ru/uploads/assets/file/gilesanuwenuxowax.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/q9p6405sc98qctj24dvqdfk5h6/vaxomubovifixosivijavurik.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bf3f70caadd---buxuzam.pdfIn PDF document text
    • http://amandatravel.com/userfiles/file/wokululereforevefagivax.pdfIn PDF document text
    • http://caratow.eu/userfiles/file/vinawujofataja.pdfIn PDF document text
    • http://aldara-latinoamerica.com/userfiles/file/fokizenakemibetegexal.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/ddcde163fdab1cee6797a103cbcf12c7/75046738324.pdfIn PDF document text
    • http://irinka.org/ckfinder/userfiles/files/dezumavixurunasevomas.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd419dcda2f---24715994212.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f14e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF14E 11012 bytes
SHA-256: 7b17579656dde9bdc11299b2c66aa917515643c7495ba2c30424091d414933fa
font_01_sfnt_off00010ae0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AE0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000122f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122F2 19132 bytes
SHA-256: b1a552cacb053c3959c386ca23bdb9da3cbec11fa09fec9ec6582d7a5518d683