Malicious PDF — malware analysis report

Static analysis result for SHA-256 81c11fe774d22843…

MALICIOUS

PDF

75.5 KB Created: 2021-04-02 15:30:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: 8e02ca205d154cc94543b459d63c419d SHA-1: 53a8b8d8d19056e0a960cbde3eca44a407c7b58c SHA-256: 81c11fe774d2284313f0985e70fb15ebb8675662006b2b5b7ec43f852f768302
146 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a callback-phone (TOAD) lure. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://golowaki.ru/award?keyword=calculus+early+transcendentals+3rd+edition+pearson+pdf PDF link annotation
    • http://misstourist.info/95459420874mib38.pdfIn PDF document text
    • http://busotokebos.iblogger.org/windows_10_size_iso.pdfIn PDF document text
    • http://theraisins.pro/6303974959mfngn.pdfIn PDF document text
    • http://aicberg.net/881305764548kdp0.pdfIn PDF document text
    • http://tgesheff.xyz/6.0_powerstroke_fuel_pump_wiring_diagramp67s0.pdfIn PDF document text
    • http://bigwin-1xbet.fun/medscape_physician_burnout_report_20196kylj.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://xuxegukazo.rf.gd/readworks_arachne_the_weaver_answer_key.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bdb90ac2-6cdf-4b09-95ba-beb6464c9347/sesag.pdfIn PDF document text
    • https://9c12218e-e157-4070-b33f-4467b3cb42bb.filesusr.com/ugd/0c60a0_94f3ebe78c554d10b70683dd6aeaefc2.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/10e0895a-f53b-4c72-8e1d-a63db5bbb4be/39764104159.pdfIn PDF document text
    • https://24218389-b518-4ca3-8548-65eaf758daa4.filesusr.com/ugd/c836c3_59dbc0e824424029ada6e58c24052053.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/1a343df5-6c41-41d7-ba84-f307d9023c7c/xibuxexin.pdfIn PDF document text
    • https://84daacc9-7e90-4c5d-b1ed-526950900c49.filesusr.com/ugd/73f3b0_69332d57123949dbbc93bf29142e64e5.pdf?index=trueIn PDF document text
    • https://810dce77-56ab-4324-823a-3549757f4eab.filesusr.com/ugd/1fad07_434f1fdd68854fef8d40d2a878f9c6f6.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/cfe3408c-f13c-4c35-b434-eb7d946418ea/child_short_stories_in_hindi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fb85f15c-ebfd-4beb-a5aa-3307d2f39dec/14250610087.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b6c72d13-61db-401a-a4e4-1685875141e8/mdr-xb950bt_not_charging.pdfIn PDF document text
    • https://e26976e3-f089-44cc-a2a6-54bcc6cae308.filesusr.com/ugd/0df15e_5b79e17fecbe4bd48a78615293ae1bdf.pdf?index=trueIn PDF document text
    • https://a5fc3680-5c08-4cda-bd6c-abaa3bdf25bc.filesusr.com/ugd/ea5d7b_910e45296ae74b4885a340b97b891c2b.pdf?index=trueIn PDF document text
    • https://84d655c4-d84a-4a0c-9c32-0387925bd622.filesusr.com/ugd/6233da_be9bc3cb08a742d9a8bddbfd75ad3d84.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_off0000e7cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7CC 5320 bytes
SHA-256: 04d761b7fc59fdd76a26719b285d6677d63c02ffd75f007eef8187665189e104
font_01_sfnt_off0000f9f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9F6 11512 bytes
SHA-256: 78e4f8bf82813aab1a2a1c8e6e65bbb68b427552fe04bbbbcb147382f5a36bef