Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a1f3b05266f6178…

MALICIOUS

PDF

71.8 KB Created: 2021-09-24 14:16:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 908b8dd4a5b09a0c0a8e81c18c7225f2 SHA-1: 533eef26b0d541cbcc3c34804d3c29121121ee9e SHA-256: 6a1f3b05266f6178598cc22c890fc837256ed1061de77a42adbc1aba40664b01
156 Risk Score

Malware Insights

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

The PDF document contains a link farm pointing to numerous URLs, several of which are hosted on compromised WordPress sites or disposable domains. 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 and URL analysis are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://mastera-mix.ru/ckfinder/userfiles/files/18803257331.pdf
    • https://bisleri.genefied.co/ckfinder/userfiles/files/nadokifawuzerusojiga.pdf
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/161423640e3375---tovobagisakeb.pdf
    • http://jullien38.com/ressource/site-image/files/jitadipito.pdf
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/7adb10f9f9e7f310569ad048484e4c54/wafojazega.pdf
    • https://pmfegypt.com/userfiles/files/bavaviwezamaxulugubi.pdf
    • http://www.ez4parcel.net/upfile/files/2021/09/14/18583419338.pdf
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/vhkimo4ghesk912jevsofbm01n/jigox.pdf
    • http://pokrowce-ochronne.pl/Upload/file/reput.pdf
    • http://otevrel.eu/ckfinder/userfiles/files/tamakovifepejufo.pdf
    • https://bela.geekers.tw/upload/file_folder/file/tavosowa.pdf
    • https://grafconsulting.pl/Upload/file/xedegevaparajama.pdf
    • http://gotoippc.com/ckfinder/userfiles/files/xolawakolaresigixofineke.pdf
    • https://alley.52886.tw/uploads/files/rizifiwe.pdf
    • http://wittlich-luexem.de/userfiles/file/72616221892.pdf
    • http://uniquecharacters.com/upload/files/75885661692.pdf
    • https://iaido-iaijutsu.ru/userfiles_exc/buxifexabalubusixedafanir.pdf
    • http://www.pattyn360.com/upload/forum/files/xegomabosabowabazukibe.pdf
    • https://anhhuynoithat.com/asset/files/81003023118.pdf
    • http://numere-mopede.ro/mm/file/67097906239.pdf
    • http://daiichihousing.net/uploads/news_file/71923551199.pdf
    • https://tort-art.ru/userfiles/file/50343848931.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=play+store+do+not+work
    • 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_off0000b335.bin
182c950271c285554d9d48cab7eb1b22beba4702079716202e0a4f5732665010
pdf-font-stream PDF embedded font (sfnt) at offset 0xB335 17964 bytes
font_01_sfnt_off0000e165.bin
ff232e6580dda18c7f32253d6194a267d36735a1cbd5443c674fe5f77717f35a
pdf-font-stream PDF embedded font (sfnt) at offset 0xE165 10440 bytes
font_02_sfnt_off0000f963.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF963 16792 bytes