Malicious PDF — malware analysis report

Static analysis result for SHA-256 4172d3748a2c9cc4…

MALICIOUS

PDF

82.2 KB Created: 2021-09-15 13:24:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 874a2bfda7d47447cbb10296254f4b77 SHA-1: 428c17656972d30f7d53a5b14c3e01530e7225bb SHA-256: 4172d3748a2c9cc4aeea20efe796928ab11c18500d81d0c9d1703798617dd5f8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to various domains, some of which are identified as compromised CMS upload storage. The primary purpose appears to be directing users to external resources, potentially for phishing or further malware delivery, aligning with a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://nakamurasangyou.jp/app/webroot/uploads/files/5856388601.pdf In PDF document text
    • https://rarahil.org.np/ckfinder/userfiles/files/nenagararowatuzebeworato.pdfIn PDF document text
    • http://dieta-plus.pl/userfiles/file/sanemosifelodegikixupid.pdfIn PDF document text
    • http://giovanninociti.com/userfiles/files/81586403143.pdfIn PDF document text
    • https://nhanloc.net/userfiles/file/43407029585.pdfIn PDF document text
    • http://www.cpiequipos.com/assets/images/user_files/files/fuwujekutosopejegagokavil.pdfIn PDF document text
    • https://datajournonepal.org/files/radutepamodisakitodekunix.pdfIn PDF document text
    • http://saothienemb.com/uploads/images/files/wipobe.pdfIn PDF document text
    • http://www.tramag.pl/upload/file/69753093492.pdfIn PDF document text
    • http://studiofantino.it/userfiles/files/23106831903.pdfIn PDF document text
    • http://fc-junajted.com/upload/datoteke/21842521502.pdfIn PDF document text
    • http://creativecoms.net/userfiles/file/58468800349.pdfIn PDF document text
    • https://chongtham68.com/app/webroot/uploads/files/13514929934.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/715bb8c7f025e4912fe523b8efb0c16d/93229356343.pdfIn PDF document text
    • http://tsrmvolontari.it/userfiles/files/rorarezedejibije.pdfIn PDF document text
    • http://itemclinicchina.com/ckupload/files/10811356606.pdfIn PDF document text
    • https://acrgroup.nl/userfiles/file/49801835909.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/dfacbe66ae45f0c58d2ae1588c5806aa/52549694829.pdfIn PDF document text
    • http://henskeschildersbedrijf.nl/upload/foruvaposak.pdfIn PDF document text
    • https://mk-promotions.com/ckfinder/userfiles/files/14925412672.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/161384ec912128---39476394512.pdfIn PDF document text
    • http://uniquecharacters.com/upload/files/modarofunuzilob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=phone+os+systemsPDF link annotation
    • 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_off0000d85a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD85A 10088 bytes
SHA-256: 889cc7c9d84e4a63d1e2173a25c2394619e863e46a43c5896c22195ac7ac0f58
font_01_sfnt_off0000eeb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEB0 20508 bytes
SHA-256: 0f751ae01f7cc924e11446de8da03c986bba402facbf8fa74a180c4a609e129d
font_02_sfnt_off0001233a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1233A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1