Malicious PDF — malware analysis report

Static analysis result for SHA-256 c86dee79dc400224…

MALICIOUS

PDF

71.1 KB Created: 2021-09-25 21:11:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a48aca5e348f0c2a421ff9fee1b2d950 SHA-1: e2b1a9b9e85c67c46b18893d74ca89882f83a91c SHA-256: c86dee79dc400224bcc7ad95b4ce6a3aa865aabae79d04b949dc0fce344546f3
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and embedded URLs suggest an attempt to lure users to malicious sites, potentially for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • 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://crysiq.ru/uplcv?utm_term=bloon+td+apk+mod PDF link annotation
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/161418e58383e1---bolesitifetenavemepa.pdfIn PDF document text
    • https://dwitunggaljaya.com/sitefiles/file/suzikekusisakuwo.pdfIn PDF document text
    • http://tongshengchem.com/ckfinder/userfiles/files/gakip.pdfIn PDF document text
    • http://zhouzhuank.com/v15/Upload/file/2021971156206001.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/qfgaduj84q0rsdov1dqanfe421/69007388404.pdfIn PDF document text
    • https://leifs-auto.dk/images/file/tipazigarijidumofimogap.pdfIn PDF document text
    • http://z500.si/files/vixebuwozefodafolomufe.pdfIn PDF document text
    • http://skinct.com/upload_file/file/Fl202109182113114349.pdfIn PDF document text
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/a313d69df3be88545dec15770da32e74/zubejeligitukaxekugitejop.pdfIn PDF document text
    • https://mimpishio2.net/contents/files/11731405602.pdfIn PDF document text
    • http://nayyaralidada.com/alpha/ckfinder/userfiles/files/73163057347.pdfIn PDF document text
    • https://www.sudicobank.com/ckfinder/userfiles/files/vukokamudesewatod.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/8dd3226b044944a7479ab59b765f1e5e/98632626975.pdfIn PDF document text
    • http://modellszerviz.hu/userfiles/file/mupusovikat.pdfIn PDF document text
    • http://ei-windykacja.pl/upload/file/72804725758.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1613310481ca63---52695491939.pdfIn PDF document text
    • http://arkystudio.eu/userfiles/files/48086650975.pdfIn PDF document text
    • http://topoint.net/userfiles/fckFile/20210912220034.pdfIn PDF document text
    • http://hyunbulsa.org/~ewedd2/userfiles/file/77588339927.pdfIn PDF document text
    • http://freetds.net/userfiles/file/8708474467.pdfIn PDF document text
    • http://heorungminhphat.com/luutru/files/56542440075.pdfIn PDF document text
    • http://fabiocaronearchitetto.com/userfiles/files/wurepitaf.pdfIn PDF document text
    • http://cycling-software.com/files/file/nilabedumovipusefejakavar.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_off0000b0e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0E5 18492 bytes
SHA-256: d2eb09cef6c042ed66c4995a89620cdb8fb39e5c98cb45cec73fc889a7d23954
font_01_sfnt_off0000e061.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE061 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f878.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF878 10208 bytes
SHA-256: 4f2ec57a2a7dabfd3341b9e7da666f041c9ca1efd09c4c66cf26871deca3b802