Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4e5a4cdc14da4bd…

MALICIOUS

PDF

90.9 KB Created: 2021-07-18 05:02:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 08ca1002198f373d134dfd6affe9d493 SHA-1: 8d40007d8b42da3e1a50494674f5dc18b1e3ad41 SHA-256: a4e5a4cdc14da4bd29b3b4f355fb37c78714e1d6cc4c4361ace5bf8a17ddf3b9
156 Risk Score

Malware Insights

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

The PDF document contains a link farm with numerous external URIs, many of which point to compromised CMS upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, but the heuristic firings clearly point to a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://occahomesearch.com/userfiles/files/24416627241.pdf
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/funukobibid.pdf
    • http://alexandraharris.com/clients/36054/File/rugifanuwoxoxodifasi.pdf
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16086852d4d8f3---gukorodamupewasujizuliw.pdf
    • https://henklinders.nl/henklinders/upload/files/41414046561.pdf
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/13a8ed9a775c9c17e901bb990b297c1f/54498978163.pdf
    • http://pronobile.de/catalog/file/86958751811.pdf
    • http://xn--knstlerische-biografie-arbeit-lbd.ch/userfiles/files/6685627598.pdf
    • http://somsit.com/ckfinder/userfiles/files/76421766688.pdf
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a4f40fbf432---58826070112.pdf
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/aa6ffd6a8f021d22c870a12407fec4cd/34987995003.pdf
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/sivm3nkifp10keev4bfv17dp17/tusedelulajujasopezut.pdf
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/5c72d8f75fd036b203cedd08109744c0/kutuwodijejavumugituwetuf.pdf
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b64737c24fc---18041044406.pdf
    • http://eros-arena-reutlingen.de/eros/userfiles/file/dugenesugoxuva.pdf
    • http://biurod9.pl/public/userfiles/file/98365848311.pdf
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b17fe5b55db---32921216428.pdf
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/8964fa81f8d22a7f2980585c0c1710a3/48483386032.pdf
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/40f639030ff166cf587213ef52d257f8/limozaxo.pdf
    • http://frangarcia.eu/upload/file/vituwutu.pdf
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/160879aff6abc1---najedexodadofebane.pdf
    • http://www.klimavill.com//data/editorfile/rotukusamimalajesavite.pdf
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/3aa53c64f3840ebcb392c1bfd23b94aa/vimetewanupokaxumumulo.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=screen+recorder+only+phone+audio
    • 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_off00010208.bin
485b2729d40dc87235cf918b7bfc36f45b707779ee16a7aac72b180d3f6cf427
pdf-font-stream PDF embedded font (sfnt) at offset 0x10208 16896 bytes
font_01_sfnt_off00012dfa.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12DFA 16792 bytes
font_02_sfnt_off00014611.bin
beb16b461f619f62a6f49cf0221703fc67b0797f1976744a119f9380daa1c1b5
pdf-font-stream PDF embedded font (sfnt) at offset 0x14611 10636 bytes