Malicious PDF — malware analysis report

Static analysis result for SHA-256 8817ce78532631b1…

MALICIOUS

PDF

86.4 KB Created: 2021-07-14 08:33:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 0ed51b366052b63082c0161d3f717c4f SHA-1: ec872e2ce069c0a8c0e3c2931b5c4ee280d87705 SHA-256: 8817ce78532631b10479e71a5b2425b1cdc0b408e1ab39d89831dd38c8220e34
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm hosted on compromised WordPress sites, suggesting it's used to redirect users to malicious content or phishing pages. The presence of numerous unknown URLs further supports this, as they likely lead to further stages of the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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 https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/4qj2sofrpmgs0e61d0of8saj2p/22353880477.pdf In PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/b59c82837b29e8059872646f19c32afd/58928238511.pdfIn PDF document text
    • http://nextgt.eu/uploads/file/25859828462.pdfIn PDF document text
    • http://www.irrv.org/uploads/files/limefasasodeturi.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/86504db56d083411b5705537fcd09832/65950775532.pdfIn PDF document text
    • http://womenshealthcarenp.com/clients/2/29/29a32d4da59f0b4eaa4573e1354aeabc/File/19501502161.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609687f0e5a56---bisavejivoxasigefilofed.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c72fa39722e---26178038131.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/bv417fb0pmig2gd0uucgj8ftq6/33739360820.pdfIn PDF document text
    • https://callhfelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d96e99d0a9---70754265740.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fae0e38540---3875164002.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/d98dd2c493b3cae08b429d76db37f4e7/vifewatolepugusafetimesu.pdfIn PDF document text
    • http://shelton1961.com/clients/35589/File/zatidubinaxazapeduropu.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/7d4b779e5c9882dc914743598cc06492/5872576413.pdfIn PDF document text
    • https://europeancustomtailor.com/wp-content/plugins/super-forms/uploads/php/files/1e50a5bb0c36bd83aa36b3da8d002969/18828290448.pdfIn PDF document text
    • https://fzclicks.com/demo/files/editor/file/xuxurizijuruma.pdfIn PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/dkl2ql8kghik1b5jm9qan3v252/53699136641.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8ec88ef05a---58084343675.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/a26b700e557226ea2032837264ee8342/memegegisaxowenuwuse.pdfIn PDF document text
    • https://mfdesign.hu/files/file/tofaz.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b958248d07d---bogafik.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/140853465e24a9ddf3045af2c5f0a691/35360997999.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/0mhd1h0tgo8j8qtms1l30i1g37/7984397759.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=create+macos+bootable+usb+from+windowsPDF 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_off0000ec88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC88 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001049a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1049A 17544 bytes
SHA-256: 9ea4830968ff4548f82bfd0aeafb16e8690d4610016fa2c0427ccbb34c3e3d50
font_02_sfnt_off00013292.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13292 10992 bytes
SHA-256: b0f1d50cc69b91722966df34767a48374b552eb5ea8659a31b3d7b5b82f49357