Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c701d587db8bfdc…

MALICIOUS

PDF

73.4 KB Created: 2021-09-05 06:36:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: e70442ef8f25a8136b3557ad9ea947d5 SHA-1: a32578e508ab2b5d8c8cb7ce234389c50582746a SHA-256: 4c701d587db8bfdcf71c9983943adc9fc8cb962584b0ef45aafd09bf2b085cd8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and exhibits characteristics of a link farm, with numerous URLs pointing to compromised or disposable hosting. The PDF structure and embedded links suggest an attempt to redirect users to malicious sites, likely for phishing or to download further payloads. While no scripts were explicitly extracted, the PDF format itself can embed JavaScript, which could be used to facilitate these redirects.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.3688

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ac9cffc7bf1---54588040029.pdf In PDF document text
    • https://kocgrafikavukatwebsitesi.demowebsiteleri.com/upload/files/tusiwanoj.pdfIn PDF document text
    • https://valve-toho.com/userfiles/file/81977758697.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c38c4843fb5---18821657836.pdfIn PDF document text
    • https://bjjewels.net/nbloom/fckuploads/file/bexusofivove.pdfIn PDF document text
    • http://streetnn.ru/data/upload/ck/files/15006274546.pdfIn PDF document text
    • http://windowsplusllc.com/ckfinder/userfiles/files/31831035882.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/1606ed56ab410f---muluzaxewupidanasitojiri.pdfIn PDF document text
    • http://casier-a-bouteilles.com/file/43303548419.pdfIn PDF document text
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1611b89f94ebb1---gomuzagimilewi.pdfIn PDF document text
    • http://lev-steklo.ru/userfiles/file/jokurowelojoribiwiwupa.pdfIn PDF document text
    • http://pleasanthillpchurch.com/clients/5/55/55aa087cacc886b2254ddcc242c0699b/File/39414485088.pdfIn PDF document text
    • https://arte-salon.ru/upload_picture/nuxux.pdfIn PDF document text
    • http://katyababash.com/images/uploads/file/26577483809.pdfIn PDF document text
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081d3fcc9b00---10857499254.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c978aaad11---vugeravekelo.pdfIn PDF document text
    • http://rebeccaosborne.com/uploads/wukegisil.pdfIn PDF document text
    • http://cuboni.com/uploadfile/hong202107042346009617.pdfIn PDF document text
    • http://lempreintedubois.fr/userfiles/lempreintedubois.fr/file/52897025082.pdfIn PDF document text
    • http://aliceinformaticasrl.com/user/pages/sufabapureledina.pdfIn PDF document text
    • https://ngusacdon.com/upload/files/vekenawipegob.pdfIn PDF document text
    • https://www.amiunaorchestra.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16077666b94bbb---gotexegotij.pdfIn PDF document text
    • http://vitaminyplus.eu/files/file/nopebepositorofiwebulade.pdfIn PDF document text
    • https://mingyi-lock.com/data/file/userfiles/files/18721980491.pdfIn PDF document text
    • http://fitviewer.de/files/file/muxavepopidanobudes.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=glucose+definition+pdfPDF link annotation
    • 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_off0000c818.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC818 10488 bytes
SHA-256: e07353d468fcdd91eff24a53db10fc7a0817b8c2b92e67777d40d8d11567ec5b
font_01_sfnt_off0000e009.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE009 17168 bytes
SHA-256: 1b82c7ff3c52ff36372acb0c4cbe9779fff35fae3d30f0bacbfaf2f9a270e36b
font_02_sfnt_off00010c84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C84 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1