Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5d28e2021124896…

MALICIOUS

PDF

80.8 KB Created: 2021-09-11 01:26:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 5fd727045d1c0e275f2c3df438eab65b SHA-1: 56f6bcfd3a6ff1447efd5a7b9992757e38d38103 SHA-256: b5d28e2021124896cd3195024f4f32a58d475cb3794462ea0349bed6be85040c
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest the document is a link farm designed to redirect users to potentially malicious sites. No scripts were extracted, limiting the analysis of direct payload execution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://checopharma.com/upload/files/bowixowopewamividumu.pdf In PDF document text
    • http://kondicionery-noginsk.ru/upload_picture/file/vodiwisalamojukas.pdfIn PDF document text
    • https://istanbularicilikfestivali.com/upload/ckfinder/files/6844003396.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138a88fe8c8b---68917247505.pdfIn PDF document text
    • https://wegofa.com/userfiles/file/97833438864.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613083558e108---70922057805.pdfIn PDF document text
    • https://lyubomiradineva.com/files/file/72944553995.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135b8f32848b---wekazenajevapudabugezom.pdfIn PDF document text
    • http://selmanoglusigorta.com/userfiles/file/30295136416.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133806c14bae---tuxifuginapudukulotuvif.pdfIn PDF document text
    • http://klimatyzacjaradom.pl/userfiles/file/44367350087.pdfIn PDF document text
    • https://buonoantonio.it/userfiles/file/37113128157.pdfIn PDF document text
    • http://szpitalstrzelin.pl/userfiles/files/25367684879.pdfIn PDF document text
    • http://adacu.org/userfiles/file/20210910055517.pdfIn PDF document text
    • http://school19-zav.ru/userfiles/file/tarodazidage.pdfIn PDF document text
    • https://daulte.ch/ckfinder/userfiles/files/ribanote.pdfIn PDF document text
    • https://valkexclusief.reviewz.eu/app/webroot/files/userfiles/files/20096897775.pdfIn PDF document text
    • https://pakistanchristiancongress.org/userfiles/file/93080533936.pdfIn PDF document text
    • http://finance-bulldog.cz/UserFiles/File/68050945580.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/1613a8285a2724---xokasimidu.pdfIn PDF document text
    • http://fabtur.ru/upload/files/88457485524.pdfIn PDF document text
    • https://taiwancy.com/app/webroot/userfiles/files/nabivagupujipovofuda.pdfIn PDF document text
    • http://farmaciacogliate.it/userfiles/files/rumosilukoviju.pdfIn PDF document text
    • http://studiogallerani.it/userfiles/files/68594065231.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=the+last+purge+2021PDF 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_off0000d56f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD56F 18692 bytes
SHA-256: ae5f23ae4034473f0c9a09e7f6da9b279c5f6dcf3d51525b352e561352b755da
font_01_sfnt_off000105be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105BE 10572 bytes
SHA-256: 1f4ec3a1429a78b6114b4906344661615298733a058fb3f7b1eeecb41d9faf89
font_02_sfnt_off00011e2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E2A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1