Malicious PDF — malware analysis report

Static analysis result for SHA-256 a635c744f4c0bffe…

MALICIOUS

PDF

94.9 KB Created: 2021-09-13 05:31:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 27f5768904f69c71b7b1077387160429 SHA-1: c00e1e97d6ce7527747637713641de74320b415e SHA-256: a635c744f4c0bffe3cbbf91e56400a38fdb2e29201d20374ffa0a48f5721b744
86 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by an ML classifier as malicious and contains numerous embedded URLs, many of which point to disposable domains. The 'SE_CALLBACK_LURE' heuristic indicates the document's content is designed to trick users into calling a phone number, a common tactic in tech-support scams and callback phishing. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics suggest a phishing or social engineering attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9888

Heuristics 5

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://burragebrothers.net/demo/jolie/beta/userfiles/files/17873535144.pdf In PDF document text
    • https://megacook.pt/site/upload/file/nivaxunovigujinogen.pdfIn PDF document text
    • http://hnsunnyfood.com/d/files/81855442554.pdfIn PDF document text
    • http://barahi.com/assets/userfiles/files/basekabetusiwesinolewamuk.pdfIn PDF document text
    • https://khmernative-rice.com/userfiles/file/kabavuganilajomatuxixebag.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133b26e20478---51972556577.pdfIn PDF document text
    • http://abnigakgdsg.friendship-match.com/upload/files/87601271624.pdfIn PDF document text
    • https://abofahed.com/userfiles/file/bawuperajasukukufosotezi.pdfIn PDF document text
    • http://ivankrivanek.com/userfiles/file/91746161807.pdfIn PDF document text
    • https://happyfun.tw/uploads/files/202109112356185211.pdfIn PDF document text
    • https://togeltop.net/contents/files/5125357151.pdfIn PDF document text
    • http://tieulongcopro.com/luutru/files/fodulisukokelalevozubu.pdfIn PDF document text
    • https://bednidhitraders.com/userfiles/file/1298980878.pdfIn PDF document text
    • http://ydchem.cn/filespath/files/20210910052709.pdfIn PDF document text
    • https://s-oil.hoakhanh.vn/uploads/image/files/miburax.pdfIn PDF document text
    • https://hram-uspeniya.ru/ckfinder/userfiles/files/mabizusoxipetudasunab.pdfIn PDF document text
    • http://lorofilmes.com/Uploads/ckfinder/userfiles/files/10319176226.pdfIn PDF document text
    • http://uekekb.ru/!upload/files/35400350608.pdfIn PDF document text
    • http://explosivedevices.ru/media/file/11550628251.pdfIn PDF document text
    • https://rallstarawards.us/nbloom/fckuploads/file/77992545415.pdfIn PDF document text
    • https://avukatwebsitesi.kocgrafik.net/upload/files/lekipimesilavolema.pdfIn PDF document text
    • http://muszempilla.com/files/file/66152343894.pdfIn PDF document text
    • http://wonikquartz.com/upload/editor/file/1630851019.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/161397feba962b---73986728632.pdfIn PDF document text
    • http://solarissoft.com/img/userfiles/files/7206400525.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=how+do+you+make+videos+your+lock+screenPDF link annotation
    • http://alessandrotria.altervista.org/areap/ckfinder/userfiles/files/19664381304.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_off00010f2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F2C 17512 bytes
SHA-256: 973d668e118b8dd391085d49635929275ffb877e0c4990d4bfbea2072e0f5f15
font_01_sfnt_off00013c40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C40 10880 bytes
SHA-256: 6147472e277d2146625e082bf8e9e0b9196a99dc1d6265d9f69b9294d8550dd6
font_02_sfnt_off00015567.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15567 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1