Malicious PDF — malware analysis report

Static analysis result for SHA-256 51100ba73e41ee2b…

MALICIOUS

PDF

82.7 KB Created: 2021-05-08 23:55:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 09680b2f3a9a29e9f482e4443c76e993 SHA-1: 23c79ddb8031c8993178f917a823528d24394730 SHA-256: 51100ba73e41ee2bce1c6f73201a856e9f01098f731323260f6cdd74395263fd
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO manipulation tactic. ClamAV and ML classifiers identified the file as malicious, specifically a phishing trojan. The embedded URLs suggest a potential phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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 contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://zajinet.ru/strik?utm_term=rock+candy+xbox+one+controller+not+working+pc PDF link annotation
    • http://kamikofonem.mygamesonline.org/word_to_converter_online_free_instant_nitro.pdfIn PDF document text
    • http://organic-ita.space/pc_de_ses_ykseltme1kevr.pdfIn PDF document text
    • https://zesajuletolif.weebly.com/uploads/1/3/0/9/130969916/texabo-jugew.pdfIn PDF document text
    • http://help-ruleviolation.com/bengali_full_movie_site_nametu37y.pdfIn PDF document text
    • https://xinawekasev.weebly.com/uploads/1/3/0/9/130969151/7327018.pdfIn PDF document text
    • http://tixaman.scienceontheweb.net/software_architect_resume_samples.pdfIn PDF document text
    • http://sakivometo.medianewsonline.com/39961855095.pdfIn PDF document text
    • http://delayikapy.xyz/nobupoxesec35dx.pdfIn PDF document text
    • http://kubosikavudux.mygamesonline.org/nist_calibration_standards.pdfIn PDF document text
    • https://xazepobuzu.weebly.com/uploads/1/3/4/5/134582826/1765622c.pdfIn PDF document text
    • https://betoxugibujimiv.weebly.com/uploads/1/3/1/0/131071043/7170941.pdfIn PDF document text
    • http://spain50off.info/financial_astrology_books_freeillcx.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/dd3d6385-3150-4bdb-85e8-f6182a536cdf/sixabub.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e1c7d236-a89f-4966-8233-953d1ec15bb4/percy_jackson_and_the_battle_of_the_labyrinth_chapter_1_summary.pdfIn PDF document text
    • https://d70b1dc8-7d09-4148-9854-e6a7cae1b87b.filesusr.com/ugd/5899d5_a6f3deea5a1f4cfe8c7ddec9f3098811.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/33049b0f-d0dc-4fc8-8026-7d2a9af983f0/74702041336.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/93b69f2f-e795-4468-852d-9d6566088d35/78972615615.pdfIn PDF document text
    • https://19972ee8-34f0-4900-8009-9f590161cd02.filesusr.com/ugd/64db51_ceee4d71567742679b894a8f2fc4a7e0.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/f6068fc9-36dc-44b6-b4bf-7e8ea6856c9e/90745727427.pdfIn PDF document text
    • https://3568c1c9-c281-4b9a-9ea9-d5d291e0176b.filesusr.com/ugd/e5d8db_93f42210eee1494ca242d6d55bebef63.pdf?index=trueIn PDF document text
    • http://jokubamobivavum.onlinewebshop.net/illustrated_encyclopedia_of_animal_life.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/82118490-9585-4341-b451-70267c711c56/les_miserables_25th_anniversary_concert_dvd.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d10ffcb8-69cf-4874-b98d-476d680e8d1a/what_is_gni_per_capita_of_india.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/da6b049a-21ca-44f2-a63f-0453f5967807/integrate_cos_x_from_0_to_pi.pdfIn PDF document text
    • https://5d3a3edc-1384-4eb0-a354-174dd54c13aa.filesusr.com/ugd/7f5dc5_a4d99fe2c67a4fb397fef0ad70c2b847.pdf?index=trueIn 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_off000102d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102D4 5536 bytes
SHA-256: 83a4d1fd1695e8a4a0c392348c0065c08a7b26274815d43e20ad341f6f761cc1
font_01_sfnt_off000115e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115E8 10868 bytes
SHA-256: 261fa0acd3bf77345769478fe8df964f1ab3d9cd7de80d72184336c10dcfb70b