Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff8cb8b172c03e51…

MALICIOUS

PDF

71.8 KB Created: 2021-02-21 22:57:00 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-17
MD5: cc3abb3311235afc22c17d0d3cf5d5c6 SHA-1: dd85558335fb3fc5a22e2c8ab3d9bb21be72cc1a SHA-256: ff8cb8b172c03e515cc136bf9fc310ce1579f6254b29de7f96084d391d21cb7f
192 Risk Score

Malware Insights

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

The PDF contains embedded links that lead to a link farm hosted on disposable domains, with one critical link identified as a malicious redirector. The document body, though obfuscated, suggests a lure related to an 'answer key', aligning with phishing tactics. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to further malicious content or phishing 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
  • 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 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://yafferge.ru/123?utm_term=reading+into+a+new+china+volume+1+answer+key In PDF document text
    • https://divupitibi.weebly.com/uploads/1/3/4/3/134328085/bece89f144eba1d.pdfIn PDF document text
    • http://fesavuxofogegil.iblogger.org/jigidu.pdfIn PDF document text
    • https://nojabepeteguki.weebly.com/uploads/1/3/4/6/134669956/971ef2a7fd92880.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4387430/normal_5ff65b306b24a.pdfIn PDF document text
    • http://pochta-24.cc/15924342353mzo7n.pdfIn PDF document text
    • http://topchambre.xyz/fudarajuwileg.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408875/normal_5fe2c09a9f12d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4460043/normal_5ff708b56926e.pdfIn PDF document text
    • http://sibasijiv.22web.org/turufufu.pdfIn PDF document text
    • https://nokaxogu.weebly.com/uploads/1/3/4/5/134520383/natatuf.pdfIn PDF document text
    • http://alania365.ru/ios_10_beta_profile_linkvmbwz.pdfIn PDF document text
    • http://familyit.pro/jafelufime9nfge.pdfIn PDF document text
    • http://present-mag.ru/monaxodiub2jj.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416302/normal_600b0eaf3d9e8.pdfIn PDF document text
    • http://harmony-market.ru/can_rice_pudding_be_made_with_skimmed_milkj65j8.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://gazobulusobu.epizy.com/65743075013.pdfIn PDF document text
    • http://mawafomixo.rf.gd/software_developer_amazon_glassdoor.pdfIn PDF document text
    • http://rugokabiko.epizy.com/newamif.pdfIn PDF document text
    • http://nixabexefoje.rf.gd/nuziwoxisevenem.pdfIn PDF document text
    • http://pijularof.epizy.com/53731339452.pdfIn PDF document text
    • http://divapikej.rf.gd/1342319667.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_off0000c6d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6D5 3752 bytes
SHA-256: 602c2d1ae61271f441f24b04dccf5e0745a20dafa591bfaa172580dda36bdd59
font_01_sfnt_off0000d428.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD428 5732 bytes
SHA-256: 887301f2416c46177a74a9744a6f83497a48c4f1241553dacd951f4c83d76d09
font_02_sfnt_off0000e7a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7A7 12660 bytes
SHA-256: 42c7374e79676b388143d9a76f4df0d5c4f5a1b746c0dcacc5bb4339bf74194c