Malicious PDF — malware analysis report

Static analysis result for SHA-256 d3c877ca83c8251a…

MALICIOUS

PDF

82.4 KB Created: 2021-04-07 17:59:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: e4d43ec2bc09d8371e4c0285668f9470 SHA-1: 1cc1ee0d94247dbb4ef30d38a591020505a8e603 SHA-256: d3c877ca83c8251a62390a3a9152b0d12f10da04c6d73d230480b27f49496286
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains an embedded URI pointing to a suspicious domain, 'midufefew.ru', which is likely used to host malicious content or redirect users. The document body, though heavily obfuscated, suggests a lure related to 'counting sets worksheets', indicating a social engineering attempt. No scripts were extracted, but the presence of external URIs and the overall detection profile strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://midufefew.ru/123?utm_term=counting+sets+1+10+worksheets PDF link annotation
    • http://qqkaxes.xyz/menibizatikuwerefiwegalot04d4.pdfIn PDF document text
    • http://liko-sneakers.com/hair_length_chartmtdtc.pdfIn PDF document text
    • http://sokuzise.iblogger.org/wirevogujapuvaroriragif.pdfIn PDF document text
    • http://sarkife.site/66384015282zyzjz.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4475559/normal_5fffe0d7a1d2e.pdfIn PDF document text
    • http://rebituzugofebo.22web.org/akiba_s_trip_trophy_guide.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387232/normal_606d5a52ec2e6.pdfIn PDF document text
    • http://repair-kompov.ru/recaro_booster_seat_reviewcqwye.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4467612/normal_5fe48a7150791.pdfIn PDF document text
    • http://blancer.xyz/66874866860mjl9d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4477877/normal_5fde12dd8cbce.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://3bcdeb60-9876-4d14-bc0a-1dd1632c647c.filesusr.com/ugd/16a96a_36b1b919807b494c8ae698d1d4762168.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/jiwotarotavuz/android_emulator_localhost_api.pdfIn PDF document text
    • http://dilabopitomosif.epizy.com/lagu_maher_zain_barakallah_arabic.pdfIn PDF document text
    • http://ketugida.rf.gd/52753560256.pdfIn PDF document text
    • https://s3.amazonaws.com/rufonali/xoxoperexumetowefebeber.pdfIn PDF document text
    • https://911f1565-2faa-4874-b261-330d521e7362.filesusr.com/ugd/f46427_01d02ac6a7b04fc48362879b24105ba0.pdf?index=trueIn PDF document text
    • https://6196a4e6-b3b5-4a85-a139-4ec84e0a53d9.filesusr.com/ugd/d01287_b02cbc4524f6437abacb867ad5e5a231.pdf?index=trueIn PDF document text
    • http://topufopotu.epizy.com/punjabi_bhangra_new_song.pdfIn PDF document text
    • https://9480ebe7-8096-4165-94d5-b35dd525e9f4.filesusr.com/ugd/07b43d_893fb7110fd24fb7b536fe3e93389a6e.pdf?index=trueIn PDF document text
    • http://kaguzawavor.epizy.com/new_york_city_street_art_map.pdfIn PDF document text
    • https://a0758896-f8c2-4fc9-8c7e-5c1738e8bc18.filesusr.com/ugd/0ce882_676c25b711bf4a75bbbeb8e56d36f529.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/napoledunadigo/how_to_disconnect_firex_i4618.pdfIn PDF document text
    • http://turegipamikum.epizy.com/61674813630.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f957.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF957 4960 bytes
SHA-256: a73814f70ccbad036d61c73563ce1d0fee53eaf5b25b25d6871d07a9219c40f1
font_01_sfnt_off00010a58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A58 10464 bytes
SHA-256: 7708d2972dc05a87df0146f2f7820dd015e35a7905ebaf396557d597f1d9d83d
font_02_sfnt_off00012e35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E35 4324 bytes
SHA-256: 1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e