Malicious PDF — malware analysis report

Static analysis result for SHA-256 ecfb813cecb1dcf4…

MALICIOUS

PDF

77.0 KB Created: 2021-03-18 14:34:55 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: d07b2261c4a54ccd6839f27545b74274 SHA-1: b3019b41801196461be62cd5cb33e56f32a3481f SHA-256: ecfb813cecb1dcf4e30924ff7320e01d6767fd285b56b0730a343a224c4e30ec
254 Risk Score

Malware Insights

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

This PDF file contains numerous links to external websites, many of which are identified as malicious redirectors or part of an SEO link farm. The document body, though heavily obfuscated, suggests a lure related to 'multivariable regression analysis', likely a pretext to drive traffic to these malicious sites. The presence of multiple critical heuristic firings, including PDF_MALICIOUS_REDIRECTOR_LINK and CLAMAV_DETECTION, strongly indicates malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://crophysi.ru/strik?utm_term=what+is+multivariable+regression+analysis In PDF document text
    • https://cdn.sqhk.co/jojojidatun/aUtKbpN/great_white_sharks_spotted_in_san_diego.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4414169/normal_6002637bbca90.pdfIn PDF document text
    • http://xadexawufomovi.sportsontheweb.net/coloring_book_alphabet_letters.pdfIn PDF document text
    • https://nojamatisi.weebly.com/uploads/1/3/1/3/131384142/9435527.pdfIn PDF document text
    • https://cdn.sqhk.co/gonuromabime/dmsdrlh/acrylic_nails_at_home_kit_uk.pdfIn PDF document text
    • http://midorezif.iblogger.org/marchioness_disaster_inquiry_report.pdfIn PDF document text
    • https://cdn.sqhk.co/veletafi/jpRzZyA/tractor_crew_mod_apk.pdfIn PDF document text
    • https://dobojadu.weebly.com/uploads/1/3/2/7/132711966/jipuxa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475985/normal_5fe704cd8b533.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4463543/normal_5fdbed6168025.pdfIn PDF document text
    • https://kerumeso.weebly.com/uploads/1/3/4/6/134641164/dbe74.pdfIn PDF document text
    • https://rotutipugav.weebly.com/uploads/1/3/4/7/134750083/tujelilopefufefiz.pdfIn PDF document text
    • https://cdn.sqhk.co/niserutom/Ljhgfij/fruit_clinic_level_46_glitch.pdfIn PDF document text
    • http://luxasireku.sportsontheweb.net/granuloma_inguinale_donovanosis.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460946/normal_6051ef4939e76.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/nijosinizo/what_are_fun_quiz_questions.pdfIn PDF document text
    • https://s3.amazonaws.com/nakevoja/aeschylus_eumenides_shmoop.pdfIn PDF document text
    • https://s3.amazonaws.com/gumegulaxi/92595881675.pdfIn PDF document text
    • http://vanudedu.epizy.com/craftsman_self_propelled_lawn_mower_parts_canada.pdfIn PDF document text
    • https://s3.amazonaws.com/mubefula/b._ed_exam_form_fees.pdfIn PDF document text
    • http://topunofiw.epizy.com/68135721298.pdfIn PDF document text
    • http://tuwutexo.onlinewebshop.net/the_stand_cast_2020_lucy.pdfIn PDF document text
    • https://s3.amazonaws.com/wetevali/6016273192.pdfIn PDF document text
    • https://www.linkedin.com/in/pooja-a-korwar-In 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_off0000ef0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF0F 5416 bytes
SHA-256: 3f6e99a420c268a14cb70de13d6088e54cdd58bfb2f634d7421d8866d0a6792a
font_01_sfnt_off00010164.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10164 10816 bytes
SHA-256: 79dc4fa959130d96ec8c41b3aa0f96581b07a459d5a7da8680bd0b013e711513