Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a6af6e2c0934bcb…

MALICIOUS

PDF

74.0 KB Created: 2021-03-15 18:37:21 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: b05916a83e21f6293e7a837ab659a6a7 SHA-1: 1ec358dbdda47528e6d7c5906dc60c63a6dc4065 SHA-256: 4a6af6e2c0934bcbd5b17853e465e6c92dee8e5c5283aed360411eac67fbd1fd
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or trojan payload. It contains numerous embedded URLs, with one prominent URL pointing to a suspicious domain that appears to be part of a link farm designed to redirect users. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the presence of external URIs and a link farm heuristic points towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 5

  • 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.
  • 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://nipisod.ru/wix?keyword=robert+half+salary+guide+2020+uk PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4464874/normal_60367b06f0396.pdfIn PDF document text
    • http://zoluwofemofuper.sportsontheweb.net/24049859123.pdfIn PDF document text
    • http://lezobul.medianewsonline.com/39945444259.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491433/normal_602f30436b067.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4481286/normal_5fdd22cf4a149.pdfIn PDF document text
    • http://roxedizusugu.mywebcommunity.org/8152702180.pdfIn PDF document text
    • https://cdn.sqhk.co/tabuguran/MPEjf3M/xowipiraj.pdfIn PDF document text
    • https://cdn.sqhk.co/puvalonu/Rnjhwhb/sparkfun_inventor_s_kit_guide.pdfIn PDF document text
    • http://zefujixa.mywebcommunity.org/18594602868.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485589/normal_602f3193f1c28.pdfIn PDF document text
    • https://cdn.sqhk.co/bifoligi/36MgfdD/69206859426.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://6d706a39-1f93-4f1a-9423-caccf7e65e71.filesusr.com/ugd/69f91f_ba4b7b4c2da44771b8539cde80b76f70.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/vukujidor/reformed_baptist_church_orlando_florida.pdfIn PDF document text
    • https://s3.amazonaws.com/labitajaxatufib/operant_conditioning_practice_answer_key.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/092b1ead-12f9-4ed6-85a6-fdd72c796ff4/is_the_darkest_minds_series_finished.pdfIn PDF document text
    • http://kawerulim.onlinewebshop.net/chrome_will_no_longer_support_flash_player.pdfIn PDF document text
    • https://a3de454e-1598-42bb-a259-4eb69c42f179.filesusr.com/ugd/fb5067_e6d6c8d440994e889c7b4c9fbf661ca2.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/38f0edc6-a448-4459-9e24-8e313fae0146/environmental_ethics_can_best_be_defined_as.pdfIn PDF document text
    • https://s3.amazonaws.com/daselex/lapomitenexagifur.pdfIn PDF document text
    • https://77a80da1-97a3-4b40-ba11-54c6d232eb66.filesusr.com/ugd/39a0fd_9f903669ff4e4da791e30d36a28b8d32.pdf?index=trueIn PDF document text
    • https://c3d762b3-5d50-4891-ab6d-43710edd2423.filesusr.com/ugd/3254bf_91ba68593101474191a31be6d60848ee.pdf?index=trueIn PDF document text
    • https://36535336-4f9e-4c0a-b1ad-3385cb5d4299.filesusr.com/ugd/15ebe2_02194d27d6c1420b97b66870a61c2957.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/4eed1d60-6f23-4f2e-9da6-565b99e60f0e/77502805550.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e192.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE192 5756 bytes
SHA-256: 1c45f870bff3ccd94e5666c379b4c51701826c29d575828bba8e287256535d4d
font_01_sfnt_off0000f533.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF533 10948 bytes
SHA-256: 21735c6a6f64b9b1437899b254adfae683ad1156d7a82ff9801c7b0950fb6435