Malicious PDF — malware analysis report

Static analysis result for SHA-256 a68cfcb8769c2f97…

MALICIOUS

PDF

84.2 KB Created: 2021-03-15 12:32:28 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 0a80b65b104f4f5b13483da073215fd8 SHA-1: 10a20f0115830066f77730adeb1d3008c28c3cba SHA-256: a68cfcb8769c2f97733d3c00e1bac26229423cafec698ed4ce046d4f94536d35
186 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to disposable domains, suggesting a link farm or SEO poisoning tactic. The primary URL, 'https://pelibifir.ru/wix?keyword=mole+ratios+practice+worksheet+answer+key', is presented as a worksheet answer key, a common lure. While no scripts were explicitly extracted, the PDF structure and heuristic firings indicate it's designed to drive traffic to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://pelibifir.ru/wix?keyword=mole+ratios+practice+worksheet+answer+key PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4404105/normal_6039f4101d95d.pdfIn PDF document text
    • http://ostanni.fun/25607760764ro7bt.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378155/normal_600c95c029556.pdfIn PDF document text
    • https://cdn.sqhk.co/giboxikewev/YkghPPS/74220539965.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4404122/normal_5ffcb2aa03b62.pdfIn PDF document text
    • http://evatopshop.xyz/1921967079k869j.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4463272/normal_6016d0244074c.pdfIn PDF document text
    • http://antinomi.design/ikea_malm_bed_frame_spare_partsn36ln.pdfIn PDF document text
    • https://cdn.sqhk.co/wugotiparo/ejf1gBu/tobitubojupederew.pdfIn PDF document text
    • https://sudikefasegez.weebly.com/uploads/1/3/1/0/131070357/5714737.pdfIn PDF document text
    • http://lovelyhouse.online/harry_potter_book_four_chapters9c6pn.pdfIn PDF document text
    • https://donibirumot.weebly.com/uploads/1/3/4/4/134463545/48be76.pdfIn PDF document text
    • https://jorosovepi.weebly.com/uploads/1/3/4/7/134706332/padigexanara_lunimerif.pdfIn PDF document text
    • http://rimka.xyz/love_heart_emoji_coloring_pages1a2oe.pdfIn PDF document text
    • https://cdn.sqhk.co/lolajelor/jgfzEjh/fofilisixiv.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/57694682-fd76-43df-8aa0-b4173d435ec9/comienzo_curso_escolar_2019_madrid.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/77d56dec-ee7c-43a4-91c8-6bc75f631eb2/delta_monitor_shower_handle_replacement_parts.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7d333a3e-b5f5-4fdc-b04e-847c3c7b9454/e550i-b2_does_not_power_on.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2df1e9d9-aa62-46df-b306-c952d6cd566f/what_is_the_best_chess_app_for_android_phones.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a15ce223-7ae0-4d96-8d01-6f04fc8f5a32/12919630951.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e4da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4DA 3296 bytes
SHA-256: ba5f48584ae57a58929740c2953f3b7b94640ebd8bbc9cf33b823ae7483b2ef5
font_01_sfnt_off0000f0a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0A7 5284 bytes
SHA-256: 9c149298953072b262035fea4c246046e34184ddcc13a370807a890ccb3c54aa
font_02_sfnt_off000102ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102BA 12716 bytes
SHA-256: 68e84ea9cfefb672850936f2905f7a11748ac7d794e28c834722a8fd8e9575d3
font_03_sfnt_off00012c33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C33 16096 bytes
SHA-256: cbc07da60fb2daf063fa4a3b9b1c559b7679e5b06427c88e4eb51d57fd627648