Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b3401f515bb34a0…

MALICIOUS

PDF

36.9 KB Created: 2020-07-09 18:29:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-04
MD5: 8dd88d84f8281bbbb430f30a0d180136 SHA-1: 56cf131fc1470c078eeaeaae59de1a261d659fb6 SHA-256: 7b3401f515bb34a0883c1377ad7c03c16b7b94d94aae6d7c99b908e4e18cbb01
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many pointing to disposable domains, which is characteristic of SEO poisoning or phishing campaigns. One critical heuristic identified a link to known malicious redirector infrastructure, and the ML classifier strongly indicated maliciousness. The document body, though partially garbled, contains a URL that appears to be part of this link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • 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.
  • 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://ttraff.com/wb?keyword=farm%20animal%20baby%20matching%20worksheet In PDF document text
    • http://files.fablegroundscoffee.com/uploads/1/3/1/8/131856071/rezages-nujaja-xinavena-nimofo.pdfIn PDF document text
    • http://files.memortazavi.com/uploads/1/3/1/0/131070389/a5b2ace.pdfIn PDF document text
    • http://files.danberkey.net/uploads/1/3/1/4/131453823/jolego_memux_puzalemozotil.pdfIn PDF document text
    • http://files.paulsfranchiseleague.com/uploads/1/3/1/4/131438249/kabuvoxije_kuvorenuzixuw_raxejusub.pdfIn PDF document text
    • http://files.corunnatrack.com/uploads/1/3/1/3/131378921/803d2fad.pdfIn PDF document text
    • http://files.arlingtonmsband.com/uploads/1/3/1/6/131606087/ddee7.pdfIn PDF document text
    • http://files.nurturedbirthservices.com/uploads/1/3/0/8/130813646/6143167.pdfIn PDF document text
    • http://files.haralsoncountyhistory.com/uploads/1/3/2/3/132302913/4438840.pdfIn PDF document text
    • http://files.townofhartlepool.com/uploads/1/3/1/6/131606673/4121719.pdfIn PDF document text
    • http://files.authorrebeccaarogers.com/uploads/1/3/1/6/131637034/wakobobo_jujorufaxeso_puxul.pdfIn PDF document text
    • http://files.rdfsports.co.uk/uploads/1/3/1/1/131163561/faf924c.pdfIn PDF document text
    • http://files.azkillerbeessoftball.com/uploads/1/3/0/8/130874518/jemizip.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://karutetok765055257.files.wordpress.com/2020/07/63518816382.pdfIn PDF document text
    • https://wosevapog526532590.files.wordpress.com/2020/07/tukovubizobope.pdfIn PDF document text
    • https://kuperira.files.wordpress.com/2020/07/803842752.pdfIn PDF document text
    • https://vopexuzufu.files.wordpress.com/2020/07/depofefizo.pdfIn PDF document text
    • https://zixesope.files.wordpress.com/2020/07/10287599707.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/39843759369.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/bizisumexu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/74523611049.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/70745323757.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000534a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x534A 5356 bytes
SHA-256: c5e41000c8a204ee4a031f0227805498bd114640a72512fe62525a3f1ba35f15
font_01_sfnt_off0000655d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x655D 9740 bytes
SHA-256: a37769292e4b5b8409e33790254f8efe8c6b1f6692485673575dd28faf5f8c71