Malicious PDF — malware analysis report

Static analysis result for SHA-256 31171e87efa06464…

MALICIOUS

PDF

73.6 KB Created: 2021-02-25 08:10:04 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-17
MD5: 8f1768ca54df939b2fda8b4f2a652f97 SHA-1: ab735627a662f5c555ad04c34ef66729344b134a SHA-256: 31171e87efa064641cdde557d925e20048b2ebc6fc64fc7dc5a8c2b97718c3b6
146 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is classified as malicious by ML and ClamAV, with heuristics indicating it's a link farm and a callback phishing lure. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the presence of external URIs points towards an attempt to redirect the user. The callback phishing lure heuristic strongly suggests the document's intent is to trick the user into initiating contact for fraudulent purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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
  • 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 https://leonvi.ru/award?keyword=how+to+set+my+adt+alarm+at+night PDF link annotation
    • https://cdn.sqhk.co/veletafi/qj4jgDZ/red_velvet_cake_recipe_easy_uk.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4454984/normal_5ff5eb0ee93d2.pdfIn PDF document text
    • http://fakixigulidol.mywebcommunity.org/40860054098.pdfIn PDF document text
    • http://raifaisentgo.online/marvel_avengers_the_ultimate_character_guidenjo9n.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416322/normal_602f8986dc684.pdfIn PDF document text
    • http://presalon.xyz/first_angle_projection_drawing7mk9v.pdfIn PDF document text
    • http://modernstyle.pro/manualidades_halloween_decoracionqbke4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464065/normal_6022b3fb794ad.pdfIn PDF document text
    • https://cdn.sqhk.co/ruwonumatag/fpcghvP/fly_wings_hack_apk_download.pdfIn PDF document text
    • https://cdn.sqhk.co/vefomatakin/SVjjigv/extreme_car_driving_simulator_mod_apk_all_cars.pdfIn PDF document text
    • https://cdn.sqhk.co/vuwonesi/Qjah5fa/dead_ahead_zombie_warfare_unit_backstory.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4412568/normal_5ff813e3b94f6.pdfIn PDF document text
    • http://fanuvowebutil.22web.org/doyles_guide_rising_star.pdfIn PDF document text
    • http://xeeewq.xyz/halo_cops_and_robberscpsnb.pdfIn PDF document text
    • http://xakovakaxevasul.22web.org/kitubudinunamuba.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/luxelula/alpine_linux_install_apk.pdfIn PDF document text
    • http://petojijoxura.onlinewebshop.net/webster_english_spanish_dictionary_online.pdfIn PDF document text
    • https://s3.amazonaws.com/wefemabeni/10226334605.pdfIn PDF document text
    • http://sodebaxekigefip.rf.gd/2007_chrysler_sebring_manual.pdfIn PDF document text
    • http://siverudatowu.rf.gd/abandoned_full_movie_2019_free.pdfIn PDF document text
    • http://wemefozes.rf.gd/apa_format_citation_book_pages.pdfIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eabb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEABB 5396 bytes
SHA-256: 4dd9ecc3973a8600dc1ff532b1cbfb17f10438e2193e2a991ef9e2dde90e6b2f
font_01_sfnt_off0000fcf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCF8 10192 bytes
SHA-256: 0b8c0d79b6cf475d0ca704cc2fb7b8ad144756d3cb20932894abe3722027a32e

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